My 40D is currently being repaired under garantee .... error99. Still when it's working it's pretty niffty in terms of the speed of it's AF. I've been waiting for the new 5D so I can go full frame. From what I've read I believe that the 5D mk2 will not give me any more resolution than my 40D. So would I be right in thinking that if I get the 5D mk2 I'll be downgrading the the speed of the AF compared tor the 40D but will be able to make larger prints without resizing?. Is that about it?