These earphones produce a nice, rich sound, and I found the noice 'cancellation' feature worked perfectly well for my needs. To be honest, it's not true noise cancellation, it's actually a combination of cancellation and isolation, but the overall effect worked fine for me when on public transport - background noises practically disappeared, and the 'monitor' feature allowed me to hear things around me when I wanted to.
My only point to make is about the plastic earhoooks (2 sets) that come supplied with the unit. Neither of the sets are the correct shape! When attached to the earpieces, they just stick out into nowhere instead of holding each earpiece securely in place. I tried twisting, bending and flexing them to try and make them do something worthwhile, but the plastic is too soft and they just flick back to point outwards again. in the end, I removed them completely - the earpieces stay in my ear well enough without the hooks, and allow me to get a good bass response. I wouldn't want to wear them while running, though.
Overall, the earhook issue isn't enough to make me dislike these earphones. They're comfortable to wear and sound better than the (more expensive) Sony ones I was replacing.