Canon 5D Mark II

Never Ever: Rent, borrow or use the Canon 5D Mark II, if you do, you will have to own it. It's that good!

Pros:

Crazy high ISO performance
Fantastic amazing image quality you have to see to believe!
Great menus, sharper, brighter, easier to read then 40D
Video, did someone say video? I love it! You will need a tripod!
Fantastic rear LCD that you can check actual photo sharpness
Super low light high ISO photographic tool with 25,600 ISO!!!
Feels great in your hands, the grip texture is easy to hold and is well balanced
Low 50 ISO allows photos at F/1.2 aperture out in bright sunlight for shallow DOF

Cons:
No Built in popup Flash
A little slower shooting then the 40D
Very demanding of lenses, high end L lenses are a must have
Huge files: you will need larger memory cards and a larger hard drive
Ultra large bright sharp viewfinder makes my 40D finder seem dim and... Read more

This was my first full frame camera. Prior to it I had owned and operated a 40D, 30D and Rebel XTi. I am a wedding and sports photographer primarily, so I have been able to test the 5D Mark II out under both of these conditions.

For basketball I used it with AI Servo, Center Point focus, but went into custom settings and enabled the AF assist dots. It worked like a dream, focusing faster and more accurately than my 40D ever had. While no, the FPS aren't ideal for sports, if you can lock on focus like this from the start, you can still achieve amazing sports photographs. Plus the fact that I was able to shoot at ISO 4,000 and not have noticeable noise was just incredible. The shots auto-white balanced correctly too which normally in the arena I shoot at is not what happens on my 40D.

My first wedding all I could say all day was wow. I was getting available light photographs I never would have dreamed of before. The new screen also made it incredibly easy to... Read more

First the good...

If you're looking for an excellent, full-frame DSLR, the 5D Mk2 is very, very good. It's at least 1 full F-stop more sensitive to light than my Canon 1DS Mk2. A setting of ASA 800 or 1000 yields about the same noise level as my older camera at ASA 400. It's autofocus system is very fast and accurate on single shot mode. (I don't think EF-L series lenses are capable of faster focus action.)

The new LCD screen is gorgeous. 3" diagonal with 900,000+ pixels. It's possibly the best quality LCD screen ever put on a DSLR. The menus are easier to understand and navigate than the 1DS Mk2's menus. "Live View" is an excellent way to do critical focusing. If you've never used a DSLR with live view, you'll love it. The only negative of live-view is that it really drains your battery and it can only be used for a certain length of time before the CMOS imager circuitry heats up, adding noise to the image. (In real-life typical shooting, overheating is not a... Read more