I usually wear Sennheiser or Sony earphones and after my CX-300's broke a few weeks ago, I thought i'd try out a different brand to see if I was missing out on anything.
Firstly, the sound clarity is brilliant, great responsiveness over different types of music and decent bass. There are, however, a number of gripes that have made me less than impressed overall with this product.
1) My ears fit the small Sennheiser earbuds like a glove, never had a problem with them at all. Ultimate Ears seem to have gone half a size up with their 'small' which has consequently meant they fall out of my ears 10 seconds after I mash them in. I bought these just before a few 26 hour coach journeys so had to frantically swap the buds from my CX-300's which aren't a great fit on the actually product, but manage to fit in my ear regardless.
2) The wire is shocking. Yes, it's rubbery and bound to last ages, but the kinks in the wire from packing and from storage won't go away whatsoever. You look like a an idiot with cable bending around in different directions coming from your ears. It also makes them more prone to hitting things like coat collars and falling out.
3) The plug is straight. Now, most earphones have this design, but once you start using them regularly and wrapping them around your player I have no doubt the wire in that part will start to loosen and break. Sennheiser do a much better angled plug that lasts ages.
So, finally, the sound that comes from these things is really good. Design flaws mar this quite a bit however, so I'd be a little more wary of the brilliant ratings on here.