I'm a owner of a Eos 5D Mkll .
And i have been happy with my Camera IF:
It have been a bit faster(6fps or more).
Have been better quality on the house
(My back to Canon with bad grip,hard to get it right,but now okay,not perfect)
If AF have been better in low light,and abit more safe.(Always hard to thrust)
If Flash have work as on 550D,60D & 7D
If JPEG's have been good as Nikon's (Now i need RAW and much time ,sadly)
If "Auto Lighting Optimizer"have work.
If movie also have 50fps and 60fps .
I had some Canon Eos lenses from before,thats the main reason to why i buy this camera and not Nikon's D700 ("Only"12Mpix) or Sony A900 (Much noise from Iso 400 AND ugly as hell,Sorry!).
This was late 2008,and now 5 lenses later i still wonder if it will be anoying to use 2 diffrent system?
I'm still a fan of Canon,but how long?
If my next Camera still will be a Canon? ,.....thats not sure,but i will never order a Canon camera again before several test have been done,and most important,i have feel it in my hands.
I dont thrust the quality of Canon products ,after my sad 5D Mark II.
But i will probebly not change my camera until 2012-13 ,and than maybe Canon is back on the top??
(Now it's hard to belive that Canon ever will be the "Dream" again,but how knows)
Sorry for my bad English.