Summary: Comfort is amazing. The sound quality is pure good. The mix amp feature is amazing if you want to hear the game differently. The wires can get annoying but other then that one of the best gaming headsets I ever had.
Summary: Starting off the ONLY reason I gave this a 4 star rating is because of the time the shipping took. I don't blame Amazon for the shipping process, but it took me 7 weeks to receive my headset and the one I DID receive was a replacement sent due to the 1st one I ordered being lost in transit. Now as for the actual Product, This thing is amazing especially if you play FPS games.
Summary: Mixamp Pro vs ACU: Mixamp pro is very simple. Which I prefer. ACU is very, very customizable. Which is nice, but not for me. Touch sensitive buttons are very annoying. ACU has less white noise than Mixamp Pro however. A40 vs XP7: XP7 is amazingly comfortable. It shuts out outside noises very well, much better than A40's. That can be good or bad depending on what you're looking for. A40's tend to hurt the top of your head after awhile and need to be adjusted.
Summary: Got mine in the mail a few days ago. Sound is very good. After playing for alittle while I forget I even have a headset on. Very comfortable. I seen people say they have had problems with the mic sliding down. Luckly I haven't had that issue at all. I hook my phone up to the MP3 port and listen to my youtube playlist while playing. I can still hear the game sounds and people talking. I thought the music would over power but it really doesn't.