Good camera but not great.

Author's Rating:

Pros: Professional images for a relatively modest price

Cons: Video capability is the best of the DSLR's but still leaves much to be desired.

The Bottom Line: 
The best camera for professionals especially journalists and news photographers. Great camera for aspiring filmmakers.

Author's Review
This is a great digital slr camera. But more than that - in the history of cameras - it's place is secure as the camera that started the DSLR - HD video revolution.This review will be broken into 2 parts. One the 5D as a still camera and the second is the 5D as a video camera as it's the first digital SLR that has true HD full frame capabilities and many of it's buyers are videographers rather than photographers.

5D AS A STILL PHOTOGRAPHY CAMERA:
DESIGN:  It's the classic Canon design which some love and some hate. Sony and Apple are much better at creating devices that are more intuitive with almost no learning curve. This camera needs to be learnt. The buttons aren't placed in the best places and even changing some of the functions to make it easier for the user don't solve the problem that this camera needs learning time before one can take it to the field to work.

 EASE OF USE: This camera isn't a point and shoot. It's not a camera that can just be taken out of the box and start shooting images with. But after one afternoon of playing around with it, one can get the hang of it and create pretty good images. This is not a "press auto" consumer product. That said it's a product that will appeal to prosumers and professionals. Prosumers can get very professional shots after a very short time learning the camera. 

MEMORY CARDS:  The CF cards are readily available and aren't too pricey. They are pretty much a standard and are reliable and can be used again and again. That said, for video they force a high level of compression and that affects image quality.

BATTERY:  Battery life is awful. That said, the still photography is much less draining on the battery life than the video which can finish a battery in less than 45 minutes. For video - a minimum of 4 batteries is recommended. 

LCD SCREEN:  LCD screen is decent as a recommendation but not more as the resolution of the screen isn't great ( the new Canon 60D has a much better screen ). For still photography one can rely on the autofocus for focusing but for video mode - the autofocus is useless and so is left without many options. There are many third party vendors that have created an eyepiece that magnifies that screen two to three times the image size of the LCD screen to help with focusing. But since the resolution of the screen isn't as good as the final resolution of either the video or the stills - focusing can be tricky and challenging in low light. 

 VIEWFINDER: Complicated to use. Not intuitive. Not enough details appear in it. After using it for a very short while I went back to using the screen with an external third party eye piece attached to the LCD screen.  

SENSOR:  21.1 MP with a full frame 35 mm sensor making it the largest sensor on the market for these type of cameras. The large sensor allows extreme shallow shallow depth of field shots that gives the images breathtaking look and allows gorgeous close ups. The large sensor also allows the ability to shoot at low light without any external light. The large sensor allows a 50mm lens to be a true 50mm without any crop - but that also means that the lens needed are the expensive full frame lenses and some of the lens sizes only exist as an L series - Canon's most expensive ones.While the full frame lenses mostly are of superb quality - if your budget is limited and you would like a lot of different lens sizes, then perhaps the Canon 7D with a smaller sensor that allows using almost all of Canon's lens lineup would be a better choice.

FLASH:  Flash is extremely difficult to master on the 5D as it's not intuitive and hard to remember what each button does and how to make it work automatically. The flashes seems to have been built only for professionals and not for prosumers. So if you don't have the budget for a higher end Canon flash ( 580, 430...) avoid the flash on this camera. Because of it's amazing low light capabilities most shots can be shot in almost darkness.

AF SYSTEM:  Relatively accurate. Not as fast as the 7D and doesn't have the same level of details and options as the 7D. Nonetheless images tend to come relatively sharp in general light. In low light focusing becomes extremely low. The AF system is only for still images. There's no decent focusing for the video. It's even slower than for the still images.

SPEED:  If speed is an issue  go with the 7D as it's a faster camera and will be better suited for sports.

VIDEO:  Currently the best video DSLR on the market. More info on that below.Sensor doesn't have a heat warming light like the 7D and thus may burn shortly after purchase.

DIGITAL NOISE: Alliasin and Moiring are the biggest problems of both the 5D and the 7D when shooting video. These are very annoying digital noises that sometimes appear on the shot images. Go to youtube and I'm sure you'll find a lot of tests and examples that will illustrate the problem in hudreds of scenarios. There is not much that can be done against it and that is what makes it so frustrating. The camera has no video filter and that is why there is so much noise in the video image. The camera wasn't intended for videographers. The video was added almost as an afterthought. AS time goes bye, videographers will learn what elements make more digital noise and try to compensate for it in other ways.

24-105 KIT LENS: The kit lens that come with many cameras are many times a cheap mediocre lens that's thrown in as a bonus for buying the camera. But the Canon 24-105 L series lens is not like that. It's a superb lens that not only has outstanding quality and is a great L series lens ( Canon's top of the line lens) but it also is extremely useful for most conditions from wide angles to close up shots. The lens only weak spot is that it can't shoot at lowlight (It's a 4 not a 2.8 or 1.4 lens) but for lowlight capabilities one would have to use a much larger lens and this one is ideal as it's relatively small and easy to carry around.

VALUE: .For the price, it's the best still and high end video camera on the market today.

VIDEO INTEGRATION AND USER HANDS ON EXPERIENCE:
My thoughts after using this camera for almost a year:

I'm a professional videographer and was looking for a full frame sized sensor camera that could shoot video on a shoestring and that's why I purchased this camera. I shoot very little still images and so my review will be of the video qualities of this camera rather than it's still image capabilities. That said, I will give my humble experience with the still images of this camera. It has a 21 mega pixel image quality. Which will probably be good enough for most professional photographers and would even create stunning and sharp images for most sized billboards.
As a still camera it's one of the top cameras currently out in the market. I've seen that many professional journalists and newspaper photographers have purchased this camera and are using it daily. It's the ideal workhorse. Excellent quality and a price that is within reach. It's also a very rugged camera and will not be damaged easily moving around. 
For the price - it's perhaps the best still camera currently out there.It has a full frame - which allows shooting in low light. The full frame allows the creation of breath taking images with stunning vibrant colors and an extremely shallow depth of field which can't be matched by any of the other DSLR in the Cannon line. 
The large sensor with the Canon glass is a winner.I've tried the Canon 5D also with manual Nikon lenses - and while the lenses are harder to operate - their image is just as great and sometimes even greater than the Canons.
Because it's a full frame- there are a lot of relatively cheap full frame lenses one can attach from older 35mm film cameras from other manufacturers with cheap adapters that are readily available on Ebay. They will not have any auto capabilities but they will still allow creating different looks and getting more frame sizes to enhance you photography pallette.

The 5D's buttons are all very intuitive and easy to use - the camera also allows you to change the function of the buttons to make them correspond to what the user would like for those used to having the buttons functions placed differently.
Canon has a wide range of lens for this camera- yet because of the full frame sensor - most of the cheaper Canon lens aren't compatible and so when calculating the true cost of this camera take into account lenses that cost almost double the price (sometimes more) of all the other Canon cameras with the smaller sensor cameras ( like the 7D, 60D, T2i...)
Zoom lenses are particularly expensive for this camera.That said, there are so many places that rent lenses for so cheap- the lens factor isn't the deciding factor anymore. Many of the greatest shots I've seen by the pros have been shot with a simple and relatively cheap 50mm lens and most portraits are shot with an 85mm or 100mm lens. Auto focus on this camera is accurate but relatively slow. So while it will work for most images - for sports photography I would also check the Canon 7D which has an auto focus I found somewhat faster in real life use.One of the greatest things about this camera is that it shoots raw images meaning you have the ability to play with the images afterwards and change latitude, colors, saturation, contract at levels that aren't possible in semi prosumer cameras.
Now for the video factor.The video image looks like nothing any videographer has seen before in cameras that cost under $50,000. I read a lot about it - but when I actually shot I was blown away by the quality of this camera's images. It has a very unique look that almost doesn't look like video but like 16mm film.  
But this quality comes at a price.The camera has a lot of digital noise - aliasing and moiring are a nightmare. You don't know when they'll creep up in the image and because this camera doesn't have a video filter that filters these noises like most video camera have -  it can ruin the shot.
Also, the CMOS sensor creates a rolling shutter effect - meaning that when the camera tilts or pans sometimes it creates an annoying strobing or jello like effect.
Sound is also a nightmare and can't be controlled manually while shooting which makes it very hard for shooting professional videos.
The camera has no headphone jack so you can't even hear what the camera records. It doesn't have an XLR input for professional audio either.

The camera is very hard to focus and because of the shallow depth of field if you're not careful and your subject moves even a tiny bit the image will not be sharp.

Because it's a still camera and not a video camera - the sensor tends to heat up and will eventually burn if you shoot video for too long. Unlike the 7D there's no warning light that warns in advance when the camera is too hot. (And I heard the warning light on the 7D also isn't that great and is innacurate). I burnt my sensor after shooting for a few days straight. When I went to the Canon facility to have it repaired there was a very long line of 5D and 7D users all with the same problem. Canon is aware of it and all they will tell you is that it's a stills camera not intended to shoot video. I asked them why then did they add the video capability and they didn't have an answer.
Although the camera isn't that expensive - adding all the additional items needed for shooting ( eyepiece for focusing, external sound system for video recording like the Zoom H4N, Beachtek or Juicedlinked systems), and all the other small items, and memory cards needed to create a full video able camera will add a few thousand dollars. Focusing will still be extremely hard and a $600 -$1000 monitor will be needed to be purchased eventually.Also, a shoulder rig to allow handheld will be needed which will run you another $1000.

Bottom line - this camera will eventually reach $10,000 to become a true video camera with all the needed accessories.

To conclude. I've shot a documentary with this camera and worked it hard for several months. I love this camera but I also hate it.When it doesn't betray me - the images are stunning and everyone looking at the images are blown away.But it's very very hard to operate. It's a nightmare most of the times. 
 I suggest for anyone wanting it for it's video capabilities to rent it for a weekend and after shooting for a few days make up your own mind if this camera is for you.It's not for the faint of heart as you will lose many of your shots but those that will come out might be worth the gamble. There's nothing like it in it's price range or even for three times that price.
Then again, I got to remember that it's truly not a video camera but a still camera and as that - it's the top dog right now. I've shot a few large press conferences with national and international press from around the world and what amazed me is that All the reporters/photographers either had the 5D or the 7D but the majority had the 5D.There was not even one Nikon dslr camera in the room. I remember ten years ago shooting press conferences and there was about an equal amount of Nikons and Canons. 
Professional news photographers usually go with the toughest and most reliable work horse.  They are a great barometer of what's the best camera at any given moment and the 5D as a still camera is currently the best on the market for the price.