I had an immense amount of trouble initially. The throttle pedal is much longer than on the T-GT, and so, combined with the nonlinear throttle, makes for a really tough adjustment period.
The feedback was good, but I could certainly feel the lack of the transducer that the T-GT has. Once I got it down though, I still enjoyed it. It's very likely a better wheel for everything outside of GT, but it's no replacement for the T-GT within the game.
Big thanks to Fanatec though, their representative was a real stand up guy.