I got the Zalman mic, I can say that it isn't that great. Unfortunately, it just hangs under your chin, and unless you want to talk with your chin down, you won't get much volume out of it.
My overall stance on game headsets are that they are gimmicky and the guality isn't as great as getting a seperate hadset and microphone.
If you want to go cheap, just get a cheap plantronics. But if you want something more, don't go for gaming headsets, instead, invest towards seperate dedicated headsets and microphones.