5 D Mk iii pros low light noise
slightly better
ease of use, the menus are far better organized.
HDR mode for in-camera editting if you're lazy like me
[/list] dedicated live mode button
Cons
need lightroom 4 to edit RAW
low energy floresant bulbs at certain shutter speeds smears colors
[/list] weather sealing not as thorough
1d mk iv pros
ergonomics
f8 max aperature focusing
[/list] 1d's just hold their value better
I own both, listed both on CL along with my 7d then never returned emails because I can't decide either.