I got the Logitech Pro Force at Gamestop last night along with the game and SFAC. The wheel is absolutely impressive, I'd highly recommend it to anyone with the $ to blow (as in SPEND THAT CREDIT on it, Fats). It's a steal at the Fry's price, Butta.
I don't normally like car sims, but with the wheel, damn, GT4 is awesome. The feedback is the best I've ever seen in a peripheral, and the construction is top-notch.
I agree with Curt 100% on the lap attachment. The little clamps are a bitch on the knees/quads, unless you get it situated juuust riiiight. And then you take one tight turn and it goes flying and it's not so just right anymore and it hurts again.
Oh, and to Fats' concern over size, it is surprisingly accommodating, IMO. I have very large hands and long arms (yes, just like a damn monkey, thanks) and I was very comfortable with the wheel, reach-wise. And the base is low-profile enough that I think it should accomodate larger gentlemen quite well.
edit: to address other questions- shifter is VERY smooth, very well-made. Feels great. Also, the pedals are smooth, too, and feel sturdy enough that they will not break. Somewhere in the neighborhood of the Steel Battalion pedals, maybe. Smoother than those, with a little less resistance.