Summary: These sound really good. I found them a little uncomfortable and loose at first so I fitted the rubber ring and foam pad on each earpiece and now it's a very snug, comfortable fit and gives a half-decent level of isolation from the outside world too. I'm surprised at the clarity of the sound, I can now hear more things going on in the music than before with my (what I thought sounded decent) Sony MDRE828, now discontinued.
Summary: Excellent sound quality with fantastic bass response. I find the in ear type headphones annoying, the bass transfer is great but I find sounds such as me breathing or my feet hitting the pavement are very intrusive and pretty much all external sound is cut off (which is probably the idea, but I find it useful to have some awareness of cars and buses etc) and these are the best I've found that aren't like that.
Summary: I left my good set of earphones on the train a few weeks back and really got quite upset about it, so I decided to buy a cheaper set that I would not be so worried about losing again. This set seemed to fit all my requirements. They are by no means expensive. They are made by Sennheiser - my personal favourite manufacturer for earphones/headphones.