Forza 2 = an absolute necessity to have the wheel
PGR3 = VERY fun with the wheel once you adapt to using it. With the wheel you'll be more likely to race a perfect line (its harder to recover from powerslides gone awry with the wheel)...in fact learning how to drift with the wheel while NOT spinning out feels like an accomplishment once you get it down, and its fun
However PGR3 is a game where I still do better with the controller in a 3rd person view, but its more FUN to play from the in-car cockpit view with the wheel.
Basically the wheel changes the way you play the racing games......at least it does for me......some games feel better with one or the other.
The only gripe I have about the wheel is that its quality is lacking...the wheel itself feels like a gigantic hunk of solid steel. The problem is the motors and the casing feel like Chinese leftover plastic, so you get the odd creak and groan from the housing, something even my 6 year old logitech wheels don't do.