I'll take the Momo:
1) 3 point mounting - the Momo has a 3rd mounting point that makes it 100% more solid when mounting to a desk. The DFP will rock forward and backward because you are only mounting to the front of the desk. The DFP is probably compatible with more desk styles though.
2) bigger pedal base.
3) I can't imagine any game where turning the wheel 2 1/2 times around is beneficial, maybe it's just me. I set my wheel up tight and responsive, using only about 110 degrees of rotation.
4)more mappable buttons aren't too important to me.
these are my opinions. I can confirm the the DFP works great with a PC, I have tried the Momo and DFP and would take the Momo everytime because it feels more solid when mounted and I have no need for the extra features of the DFP.
If you're looking for an even better price, Just Deals has refurb'd wheels for cheap. I bought 3 Driving Force Exs and they all work great for my 3 PCs. Momos are $47...
http://shop.store.yahoo.com/justdeals/lomorawhandf.html
edit:
wingman driver page, notice suppoort for PCs added in 4.60
http://www.wingmanteam.com/latest_software/latest_soft_xp.htm