Hello, I recently picked up a pair of the tactic 3D alpha's yesterday as soon as I saw them on sale in Canada. They're great considering the $50 price tag and superb positional sound. My question is. Would upgrading to the Tactic 3D sigma which sports 50mm instead of 40mm driver units make any difference? I play a lot of CoD, L4D2, Crysis and pretty much any FPS game. But I also use them for listening to music on my smartphone/ipod and they're a tad quiet. I'm willing to pay for the Sigma's but what would the improvements be over the 40mm version.