Razer.
Speaking from experience, independent drivers are an absolute must. The sound is just that much more positioned.
Not so much for music, not unless you actually like the sound they produce (it's slightly different).
As for being a gimmick or not, gaming headphones I mean, it is. You don't need gaming headphones, but they certainly make a difference. I know this because I've tried them, and for FPSs, it makes a difference. It's night and day in some cases.
But again, you don't need it. And spending the money on a nice set of 2.0 headphones will get you more conform, better sound quality and usually better reliability.
On the other hand, a TRUE 5.1 or 7.1 headset will get you more frags.
Priorities mate... Priorities.