Thumbs up to Sennheiser

I am in no way an Audiophile, but I am able to discern between qualities of sound. I've used many different headphones in my time, both open and closed styles, and Sennheiser always tops the list for quality.

Design
The PX-200 model collapsable headphones have a black plastic and brushed aluminum finish, which accent each other rather nicely. The earpieces themselves are covered in a "pleather" material over foam (I'm assuming). They are light, and comfortable to wear. The only discomfort I've felt is if I wear them for too long a period, the trapped air between my ear and the earpieces creates a buffeting effect that I'm not sure other people experience. It is only slight, and is easily fixed by re-setting the headphones on my ears.

Sound Quality
Due to the small size of the earphones, you'll have to play with them a little while to get them in a perfect position over your ears. But once you do, they get a full sound out of them. The bass is powerful compared to other headphones of this size, and compared to some other speakers and headphones, the highs and mids are not as "tinny". I can't give you a big detailed description on the sound, as I stated before I'm not an Audiophile, but compared other headphones I've used, the sound is amazing. Once you set them perfectly on your ears, the bass pounds, and you can hear every little detail of your music.

Portability
The PX-200's come in their own carrying case of black and clear plastic. The earpieces rotate in, and the headphones fold into itself. It fits snugly into the case, which also comes with a place to wrap the audio wire around. Though very portable, the case will have trouble fitting into your jeans pockets or other smaller pockets. But will fit easily into larger pockets and bags.

Overall this is a great product. The retail price may be above what the casual/average listener will be willing to pay, but there are deals that you can find on these headphones to get them cheaper. Also, I think it would be well worth the money if you enjoy getting a cleaner, fuller sound out of your music.