For me the 6D is the real successor of the 5D (Mark 1). Noone who owns a 5DM2 or 3 will jump on that camera. My 5D is still a wonderful camera. Everybody is complaining about the AF. No problem for me, on both cameras (I also have a 40D) there is anyway only the center point activated. May be old habit from SLR times but I am used to it. Why I am thinking of buying the 6D? Main reason is ISO range because I like low light photography. Can't wait to see this camera.