I did try out the amp with my Noontec Zoros (to kind of reduce the bass boominess of the included headset). I do think this is worth the asking price for the complete package you get.
One nice feature: you can control the game volume and the chat volume from the inline controller easily, which I think the cheaper.
Again, after a bit more testing this week (including more rigorous testing this weekend) I'll report back. I plan to try out the amp w/ the following HPs (only ones I have):
Monoprice Headset (included)
I'll let you know impressions later in the week.