I would not buy a MKIII until they fix the AF issues. You might not THINK it has this issue,because you didn't use it in conditions that cause it.
Stay away from it until they fix it. 40D is amazing with AF.
Did you try it or are you just saying some users have said?
I have trier 4 different MarkIII bodys without any problem. We have to be carefull on internet since everything travels very fast. Some people might have some difficulties with some equipment just because of user error. I have talked with many professionnals and many users which do not have any problems. Some might be off, thats what chain production is.
It is the same with Backfocus. As soon as someone shots a couple of frame OOF, they say they're lens is back or front focusing
I currently own the Canon 40D but it his going back with full refund. 1.6x crop is not for me and in noise comparison that I have done for myself, the images are the same to my MarkII.
I print as large as 16x20 but I haven't printed anything from MK III yet. I'll be ordering some prints soon and I'll let ya know. I mostly print from TIFF so I don't think resoultion matters. If I'm wrong I'll be corrected by somebody here. 



