Canon 1D MkIII MF lenses compatibility

[BRunner]

I'm thinking about selling all my AF Pentax equipment (except one body and two zooms for hiking and use with my Pentax-M collection) and go for used 1DmkIII body for my AF shooting.
And I like the idea of using more MF lenses (Olympus, Nikon, Exa) on this body with 1,3x crop.
What about the mirror compatibility? It's better than 5D? Comparable to 5DmkII or even better? (due to the crop) I found lot of information about compatibility with 5Dx bodies, but unfortunately not much info about compatibility with 1D series...

[rpo83]

This is one of the best resources i have found...

http://www.pebbleplace.com/Personal/Start.html

It mainly covers Leica and Contax..