This review is from: Creative EP-630 Noise Isolating Earphones (Black) (discontinued by manufacturer) (Electronics)
To compare these with the set of Sennheiser MX 580s bought a while ago. The Creative's in-ear configuration works better for me, as they plug in and hold in place - the Sennheisers are not in-ear and have a habit of falling out.
So, what about the sound reproduction? Both sets are crisp and clear, although the larger diaphragm Sennheisers do beat the Creative offering by a short nose if it's beefier bass you're after...before they fall out: the EP-630s are very good, but not surprisingly, the initial comparison gives a brassier, more mid- to upper-range emphasis.
At least one other reviewer comments that the EP-630s "loosen up" after use and the bass response improves. Hmm, possibly. Can't say I've noticed: it depends more on the balance settings on your sound card or amp.
Overall, the EP-630s are a well made, quality set of plugs, do a good job and the in-ear configuration is to my preference. They're less than half the price of the Sennheisers, so would also judge them good value, given the performance is (subjectively) very similar...and they don't fall out.