The Siberia headset does not offer an overly magical audio experience. Music, and sounds in general, are a lot flatter than with other headsets in the price range. Also, with the volume turned up, the sound quality falls off a cliff. It's better than what a cheap pair might offer, but the sound quality is useless compared to other headsets in the price range.
There is no cracking or background noise with or without the extension cable, but the quality is still less than spectacular.
The headset meets the sound-quality demands for Skype and other VoIP applications, but for the $79 asking price, there are far better offerings on the market. The odd cabling and microphone setup alone makes them worth a pass.
While more expensive, the SteelSound 5H deserve the win since it outperforms the Icemat Siberia on every level, with superior wiring, microphone setup, design and sound quality. Even if you want to stick to the price range of the Siberia, there is plenty better from which to choose.
Of course, the owner of the two brands is the winner here - though Icemat and SteelSound are two different brands, the parent company, Soft Trading ApS, is the same.