When designing this camera Canon actually asked photographers what they wanted which was very nice of them :)
Hence the 7D was born with an 18MP sensor (APS-C size), 8 frames per second shooting rate, a 100% view finder, HD video recording capability and easy menu navigation.
I upgraded from a Canon 400D as I already had lenses for that and didn't want to change to another manufacturer. And my word I'm glad I bought the 7D.
I had a play in a few shops before taking the plunge and actually buying the camera as I am an enthusiast and not a professional who makes money from photography. The camera isn't cheap, £1299 seems to be a common price for the body only and if you want a lens with it add another £500 on top. I purhcased mine with the 17-85IS lens and spare battery which came to a reasonable £1799 through Park Cameras.
Having owned two of Canons other D-SLRs in the past, namely a 300D and then a 400D, a few things took me by surpise when I first started using the 7D. The 7D is built very well and the exterior is weather proofed with a sort of rubber coating meaning you can use it in the rain or snow and not worry too much about it, just don't think that means you can submerge it!. The coating itself is quite pleasent to hold and touch. I've used mine in the UK and in Spain where the temperature was 24 degrees which I thought may mean my hands would start to get sweaty holding it but they didn't. The body of the camera is made from magnesium meaning that it can take a good few knocks and bangs without too much worry. It's worth remembering this camera is aimed at the semi-pro photographers who demand a camera that is a work horse and not just a play thing, and boy does it show. Compared to my old 400D the 7D dwarfs it size wise. I always found the 400D quite small to hold and therefore it wasn't always comfotable, I'd find my hands or fingers seizing up after a while. Fair enough if you have small hands that's not going to be a problem but for people with shovels as hands it gets quite tiring. The 7D, partly due to its size, has well spaced controls and buttons which all seem to fall to hand (or should that be finger?) easily. There are a few differences between this and cameras such as the 450/500/550/40/50D models. Some buttons have been moved around, there is an additional Q button that accesses the most common things without having to go through menus, there's a nice 3 inch LCD screen which automatically adjusts itself depending on the brightness of the surroundings and the view finder covers 100% of the shot.
I appreicate that last bit may sound odd but a lot of cameras with smaller sensors than full-frame crop the image in the view finder so you always find there is more in the final picture than you first realised. Quite annoying sometimes.
The dial button is located on the top left of the camera along with the on/off button which although a simple thing means you'd struggle to accidentally turn the camera off which I had done a few times on my other cameras due to it being on the top right, which is where you tend to hold a camera.
Like Canons lower models there are automatic modes on this camera but only two. The Full Auto mode will do everything for you setting the aperture, exposure time and flash if needed. The other mode is Creative Auto which gives you a bit more control over the camera meaning you can alter the depth of field, colour tone, brightness and a few other things but the camera will still do pretty much everything for you.
From there there are five further shooting modes and three custom modes. As normal there is Program AE (camera will select both shutter speed and aperture), Shutter Priority (you select the shutter speed and the camera will alter the aperture), Aperture Priority (you select the aperture and the camera selects the shutter speed), Manual Exposure (you select both shutter speed and aperture) and finally Blub (shutter stays open for as long as you press the release button).
There are also three further Custom modes which enable you to have pre-set settings but to date I haven't used these as I really haven't needed to. I'd imagine that for professionals it would be useful to be able to just flick straight to different settings that you use a lot without that fear that when you turn the dial to a different mode you lose the settings.
On the top right of the camera is a small LCD display which provides the same information as in the view finder. It also doubles up as a menu for when altering ISO, AF drive, metering and so on. A nice feature I found compared to my older cameras was that if shotting in the dark all the aforementioned things were selected on the very bright rear LCD panel meaning at night it would take my eyes a few seconds to adjust, the LCD panel on top on the 7D illuminates but not too brightly meaning changing settings is easily done whilst saving your night vision.
The menu's on the new Canons (including this) are very simple to use. I tried a Nikon a while ago and found the menus confusing as you seemed to have to go in to one menu, then in to another, then in to another to access certain features. Not so on this camera, all the menus are well laid out and easy to read. Navgation is done via a small joystick type button, a scroll dial and a button in the centre of the scroll dial. May sound odd but believe me it's a piece of cake! The menus are also in full colour which is a nice addition.
The fact the camera is 18MP means you need a large memory card, although I'd certainly recommend carrying several. The 7D allows you to shoot JPEG and RAW simultaneously which I do as I do prefer working with RAW images for post processing. A full size JEPG will take up around 6.8MB's on the CF card, at the same time a RAW will take up to 25.8MB's! That means you can fill a 4GB card very quickly. The worst I managed out of one of my 4GB cards was about 120 images (so 240 as I shoot RAW and JPEG) and a few minutes of video.
You can alter what size of JPEG or RAW you want though so remember the above figures are maximum values. The manual does quote that if shooting JPEG only at max resolution you can get 593 shots on a 4GB card or 155 RAWs.
I have always found them on the low side though so you should be able to add a few on to the quoted figures.
Frame rate is very impressive shooting at a rapid fire rate of 8 frames per second and it will take burst of up to 94 continous shots at full JPEG size or 15 RAWs. May sound pointless but for sports photography it is brilliant as you don't miss anything. You can slow it down though to 4 frames per second or single shot. There is also a two second and ten second timer on it. To be honest I leave mine in single shot most of the time but that's partly due to the type of photography I'm in to. 8 fps is very quick and I have tended to find that I take a minimum of two photos as I can't get my finger of the shutter button quick enough! 94 continous shots sounds impressive, and it is, but that's only twelve seconds of shooting!
The image quality itself is very good from the camera as you would expect with clear sharp pictures pretty much all of the time. There have been one or two problems with people getting bleeding from the past image but this has now been rectified by Canons firmware update for the operating system. Personally I have had no problems whatsoever and do quite a bit of processing in Photoshop and have never seen any bleeding on my images. If I have got any poor images it's because of me rather than the camera!
The 7D also allows 'live shooting' unlike most of their other D-SLRs. Although not a new concept to people as all compacts do this (show the image on the LCD which acts as a view finder) its a new addition to cameras fitted with movie recording on them. I haven't used it for photographing things yet so don't feel I can comment whether it is useful or not.
I think the main reason it is on the camera is because of the movie mode. The camera allows full HD to be recorded which I have played around with a bit and am blown away by the quality. There are several music and film producers who are actually using 7D's (and Canon 5DMKII's) for shotting their videos which should tell you how good it is. The manual recommends that if you are shooting movies on it then you need a card that has a read/write speed of at least 8MB per second. Not many fall below this now-a-days but it's worth checking just in case.
The camera offers three movie recording sizes; 1920*1080, 1280*720 and 640*480. It also within them offers different frame rates. In 1920*1080 you can shoot at 30/25/24 frames per second and in 1280*720 or 640*480 either 60 or 50 frames per second. Movie recording is quite memory intensive though and a 4GB card will only store 12 mins of footage at 1920 and 1280 or 24 mins at 640. If you are going to do any decent amount of videoing I'd be looking at getting a 16GB CF card minimum.
The battery life is astonishing on this camera. I have done some time-lapse photography with it and it's stayed on for 8 hours taking a 30 second exposure every minute and after the 8 hours it was just flashing at me to change the battery. May not sound a lot but other photographers have reported managing to get upwards of 2000 shots and not even getting below 50% battery charge.
One big thing I have found that eats away at the battery is the sensor cleaning feature. If you turn your camera on and off a lot it is worth, at least in my opinion, turning this feature off. I now leave my camera on when out shooting but set the auto-off timer to 1 minute. This stops the sensor cleaning every time it gets turned on or off and also means when you tap the shutter release button the camera is ready to shoot in less than a second.
There are far too many features to go in to on here, I could go on forever, but if you are finding that your current 450/500D or even your 40D is starting to get a bit limiting the 7D is the next step up and it doesn't disappoint. Up again is the 5DMKII but at nearly another £1000 on top of the 7D it's a serious amount of money for not a lot of extra kit (apart from the full frame sensor).
The only thing I don't really see the point of and haven't used is the level in the camera. You can get it to put up a spirit level on the LCD back panel to show you when the camea is not only horizontally level but also vertically. I understand why it's on it but can't see the point although I don't do too much landscape photography which is what it's aimed at.
The 7D is a serious bit of kit designed for tough use yet also be comfortable and easy to use. For me it easily gets a 10 out of 10 (or should that be 5 out of 5)! I know I've titles this, "A serious bit of kit at a not so serious price", and that some will think that £1799 is a serious amount of money but when this camera is compared to the pro-sumer cameras which it very nearly matches, it's an absolute bargain. I can't see me parting with this for a long time to come.
A serious bit of kit at a not so serious price. 
nice revie, i bought it :)