Just picked up a Logitech Driving Force GT this morning, pretty nice (it's the next one up from the DFP).
I had a G25 which I sold about 10 months ago, so I've got a decent idea of the difference between the two. The pedals on the GT are kinda on the cheap side, i.e. plastic and quite light (compared to the heavy/drilled/metal pedals on the G25), but they have decent resistance so they do the job (no clutch though). The wheel on the GT is about the same as the G25 I think, and the quality is about the same. You don't get the big sliver flappy-paddle shifts behind the wheel on the GT like you do on the G25, you just get two smaller buttons instead... which are okay but not as nice. No separate gear stick unit on the GT either, just a single up/down stick attached to the wheel base. The FFB on the GT feels very good so far, much like the G25.
Depends how much you want to spend, get the G25 if you can afford it (or G27 if money is no object ), but if you dont want to spend too much, I think the GT is a good option.
i brought a Logitech Driving Force GT last week for my ps3 (gt5p) I must say for the money it's amazing still stuggling to get use to the wheel in gt5 but it's so reward when you pull a fast lap.
I tried the wheel in win7 with the need for speed shift demo and it work fine apart from the wheel being set to 200 degree instead of 900 degree but that's because i didn't install there drivers from there web site but all in all for the money i can't see you beating it .