Now that is interesting.
Why the switch? Were you after something specific that the 5D MkII has that its predecessor didn't, or just fancied a change?
Ha Ha, because I could.
My wife and my mother gave me £500 each for my 50th birthday, I sold my 5D and grip for £850 so it cost me about £130 extra to upgrade.
But, after getting it I realise it is so much better overall than the 5D.
The screen is brilliant, 5D's screen is crap, always hated it even compared to my D200
Live view is amazing and for tabletop stuff indispensible,
AF focussing is slightly better,
Af micro adjust, well all cameras should have this,
Sensor cleaning, not had to retouch a dust bunny out yet.
The quick setting screen function is brilliant
High ISO quality is great
Slightly faster drive, not something that bothers me though
And I have not even tried the video properly yet, okay I shot a 30sec clip just to see if it worked and then deleted it, not for me.
I suspect there are other things I like about it, but those were the things that come immediately to mind.