[Rover]

The big plus for FF is the ability to get more shallow DOF. You can get wide angle just fine on APS-H, with for instance a Tokina 12-24mm f4 DX.

 

The 5D has a particularly nice colour in its files, a richness and contrast that is attractive. Similar to the 1D mk III.

I found that F/4ish on APS-H gives plenty of that (and usually I still have to stop down even more to have acceptable depth of field). YMMV. Either way, I'm not sure the difference is going to be noticeable between FF and APS-H.