I've been using HS 50 for about a year and it certainly gives A4Tech a run for its money.
On a first sight this model looks uncomfortable BUT it's surprisingly comfortable and feels very light. After hours of listening to music, watching movies or gaming I didn't feel any strain on my ears and didn't get any headache. Headband is easily adjustable and it's composed of very thin flexible plastic coated with leather and the other part is made of metal so it's harder to brake it. The 2m cord is long enough to give you some movement freedom. The volume control is on cord and includes mute button. Microphone is linked to headset.
Sound on this headset really exceeds my expectation! I'm a big fan of games like Counter Strike Source, COD etc. and this model fulfills all my needs. Sound is very clean without distortion or other unwanted noises.
For communication over Skype, WLM or other chat programs it's great. Microphone is very good and people you are talking to are satisfied with sound quality that microphone's producing. Also HS 50 does a good job at blocking outside noise.
In case of watching movies, well that's other story. Bass isn't quite good, so it can't really handle explosions and other effects of a movie. According to this, listening to music can be less enjoyable if u like techno or some other similar music genre.
The A4tech HS 50 is a really great product. It has really exceeded my expectations. For a cheap price it rivals other headsets. If you are not too picky this headset is highly recommended!