Well, im using DFP for about year now. It's good for its price, and had no problems at all!
Force Feedback could be better, because sometimes it just doesnt feel right, like, when you are driving with, ehm.. lets say 720 degrees, it is a bit too slow.
Its more fun to drive with Driving Force Pro, because you can adjust how much degrees of rotation do you want, and so, it will be more realistic.
I have played LFS with both those wheels, but i think that mine DFP is slightly better than Momo, but thats just my opinion. I would suggest you to buy
DFGT . Yes, it looks like a shi*(%*%^$^t, but it has better force feedback, and it isnt so old. And of course, try to test DFP by yourself, so then you will be able to see, which is better.
Hope this will help you to decide!
Sorry for mistakes.