I have an EX1 and 5D MK II. I do documentary films. I'd never give up the EX1 for the 5D. 5D still has way to many work around issues and for me the Sony has consistently better day to day image. Yes the 5D can do amazing things but you have to work harder at it and you are never really quite sure what you are getting. I'm sure the 5D MKIII will be closer to the bullseye.