I purchased this product mainly so that I could leave it plugged into a usb hub under my desk and have my headphones permanantly connected to it (meaning that only 2 cables go to my laptop, power and usb)
I was pleasantly surprised at the huge increase in sound quality too. With headphones the volume is a lot louder than plugging directly into the motherboard, if you have to have the volume on maximum all the time, this little amplifier will give you a much needed volume boost. Bass is also stronger with this sound card, and with the eq controls you can tweak the sound to your liking.
The included software also lets you use something called dolby headphone, which simulates surround sound using headphones- it actually works really well and now I can't live without it in games, where you will hear noises convincingly from behind and in front- not sure how it does it but it really works.
It is really cheap, at just £30 (although you can feel it in the build quality and design of the unit), so if you're using a laptop and can't install a pci sound card this might be the next best thing to get better sound quality. Recommended