Unfortunately, in use, it pales in comparison to the first-party offerings. The first and perhaps most grievous problem with the
Firestorm Powershock is a wildly inaccurate directional pad. Perhaps the developers of the controllers were thinking that not many games use the D-Pad any more, but a number of them do; most notably,
Extreme G3 uses it for weapon selection. It was therefore extremely frustrating to find that the D-Pad misread regularly; for a while I thought that you navigated the menus in
XG3 by pressing left and right, only to find that my pressing of those directions was actually also triggering the 'up' and 'down' switches. Argh. You may find it miscueing at random times, even when you're not touching the pad, so be forewarned.
If that were the only problem with the Firestorm Powershock, it would still be semi-usable for many games. Unfortunately, that is not where the controller's problems end. Instead of following the design decision made by Nintendo, Thrustmaster made the two analog sticks have a 'round' base--the standard GameCube controller sticks rest in a sort of octagonal basin, allowing easy shifting into the cardinals and diagonals with the analog stick. Because the Firestorm Powershock doesn't do this, games which rely on the angles provided by the standard controller suddenly become considerably more difficult to play. For example, a hard turn in Wave Race: Blue Storm is done with the down-left and down-right diagonals, but you basically have to guess with the Firestorm Powershock. That's not terrible, but the stick itself is nowhere near as 'smooth' as the standard ones. I found my vehicles jumping around much more than they should in the games that I played with it; I took out my first-party controller to make sure it wasn't just my imagination, and it was definitely issues with the controller.
The shoulder buttons are also considerably less sensitive than the ones on first-party controllers. I could gently rest my finger on them and give a slight squeeze to throw my weight in Extreme G3 on the normal controllers; here, I have to press harder, and the buttons don't cup my fingers quite as nicely.
I can't help but feel that the production of the Firestorm Powershock was rushed more than necessary, to make the launch of the system; most of the bugs with the controller should be fixable with some intelligent engineering. Until then . . .