I'm sorry but I'd have to disagree with you. I'm a little bit of an Audiophile and you can clearly hear a difference between 2, 5, and 7 surround sound. You can't hear it to the extent of a 'real' surround sound setup in your house/room, but you can hear it much better than 2.0 in a headset.
The problem is finding movies/games that support 7.1 sound. As a side hobby, I'll usually remix songs that I love (big fan of Trance and DJ Tiesto) and port it to 7.1 surround in a headset/speaker setup
Also, you do know sound enters your ear at the same place, it's the angle at which sound hits the little hairs (or something like that.. can't remember from Health 101 back in college) 70cm away would get way better angles, but the a good, quality headset can get that same angle no matter the distance.. in no way is the Megalodon 'perfect' but it makes 7.1/ 5.1 just fine