I bought these at the end of January because I had a pair similar to these previously. I'm a teenager with average sized ears but I can't get the right one to fit in my ear properly because the loop on the earphone is just to big. Also, I keep loosing the additional attatchments that come with the earphones. I lost the green bits that go over the actual earpiece within about two weeks because they come off very easily and now I've also lost the sponge ones as well. Finally, the right earpiece started to do that annoying thing where the sound becomes distorted, so i took them apart and twisted the wire, so they work fine now.
I think that the sound quality is very good on these earphones, but if your a female I would suggest getting just the normal in-ear earbud ones (black on play.com) because they would have fitted my ear better.

was dissapointed with the sound quallity when i first got these but after about a months use this totaly changed and are now great. fit in ear is not perfect (but are any in the ear earphones) have never came out my ears when running or mountain biking. could not do without at the gym.

Whilst adjustable, I can't get them to fit snugly in my ears with any of the additional fittings. This means while sound quality is good if I'm holding them in, it is greatly reduced with normal wear. As far as I can tell it's the cross bit that isn't long enough and whilst I can pull them into position they don't stick.