I am a long time watcher on the forum. Great place to learn. I have been shooting cropped-frame Canon cameras for 8 years. Started with a Rebel XT and have worked my way up to a 7D. I never believed I would be interested in FF cameras since I mainly shoot birds and other wildlife and always wanted the crop. But when the 5D Mk III came out I will admit I was intrigued. I then decided to rent a 5D Mk II just to see how bird photos looked (took over 5000 photos in 13 days). I was amazed at the quality of the photos from the Mk II and to my surprise how many more keepers I had. The color is beautiful and the detail is amazing compared to the 7D. Birds in flight captured beautifully from quite a distance. And not only that the noise was greatly reduced. I hate to shoot with the 7D above ISO 600 but I could bump the ISO to 1200 and even higher on the 5D and the photos were less noisy than a 7D at 400 (IMHO). I'm sold and I bought a mk III! The big brown truck will be here next week. Can't wait! BTW, working with a 5D MK II was (overall) really no different than working with the 7D. That was nice for the learning curve. I am still keeping the 7D. It takes great photos too!