So im buying new headset and I cant decide which one to buy. Razer Carcharias or Speedlink Meduza?
Which one should I buy?

Well, Razer has all technical info (in numbers) in their site while Speedlink only says stuff like "brilliant voice transmission".
I don't know the prices but the Razer Carcharias seems better to me.

From headphone experience:

If there aren't concrete numbers buy marketing terms like "lush mids" "trembling bass" "sparkling highs" or the dreaded "made for iPod" it's usually aimed at the less knowledgeable mainstream consumer. This means that they'll also be getting away with lower quality and such. For example: Bose. Never found any specs on their products. Cuz they suck (especially for their price)

I'd buy razer since all their stuff I've used have been great quality. Look at reviews though and note the soundstage since you'll be using them for gaming. Dunno how far any headsets gonna go for sound quality though :P