I've been pretty displeased with the sounds coming out of my lower-range headphones and picked this up at the local big box store. Most people will recommend the Sennheiser 280's on Amazon, which are about the same price, and apparently do a better job.
Not having the other pair I can heartily recommend this set. Build quality seems quite good (all plastic construction), and it's extremely comfortable to wear for long periods of time. There's a nice foam padding for the ear cups and a nice foam padding where it rests on your head. The cord should be long enough for most activities, and it includes a stereo adapter as well.
For sound quality, these are 'closed cans' and don't really suffer from the tin can effect of some other similar headphones. Additionally, because it's basically sealing out the outside world, there's very little 'leakage' both in and out of the headphones. This has the positive effect of not annoying your neighbors at the library, and of making the sounds reproduced that much crisper. For lack of a better term, you can 'hear' the silence in a good way - no hiss or blending of sounds from other instruments or vocals. Now, sound quality and range are quite subjective to the listener. But for my part, sounds are generally well represented and well reproduced throughout the entire range, and it is slightly tuned to the bass end of things, but not overpoweringly so. Simply put you will hear sounds on this that you did not hear on your $50 headphones.
Additionally, for portable players, I've found that, due to the impedance and ability to block outside sounds, you can basically listen at the same level from less volume or 'output' from your ipod or such.