I'm really loving the movies with my Sony NEX 7.
I had a Canon 5D, but never got used to how heavy it is.. so the Sony was a blessing.
The first problem I found on both is someting I didn't know before I bought any of them: Movie clips have a time limit... And that is crap when I try to record my bands concert for example. I hit the REC button, I go on stage, and It only gets 30 mins of concert :S
After some googling I finally found something to resolve that limitation: infiniREC - http://infiniREC.bymac.org
This stuff is a simple infrared remote that orders your camera to restart recording as soon as the camera reaches the time limit on the clip. That way I can record for hours!
Works great on my sony NEX and they have a model for CANONs too, so too bad I dont have my 5D anymore :S
I did spent a lot of money 6 months ago on a Sony VG20 to get over this limitation... I wished i knew about this little gizmo before.