I got the wheel for about 3 weeks almost now. It's great, but I don't play iRacing though. Used it with F1 2011 instead and it's a great wheel. Compared to the GT5 wheel it will let you steer much more precise. Also the on the wheel shifter paddles are bliss. A definite must have if you're a open wheel racer!
The grips are made of rubber, but feels nicer and you have more grip or so it seems then with the rubber on the GT5 wheel. The buttons are layed out just right for your thumbs to reach. Although the d-pads below are a bit hard to reach maybe. But who uses a d-pad while racing a lot? Just use it on the straight and it'll be fine.
The wheel is made of the same quality if not slightly better then the GT5 wheel.