I bought these earphones to replace my Sony noise-cancelling earphones that recently broke. (I bought my old ones about 3+ years ago and can no longer read the model number, so I can't say what they were).
Initially I was very impressed by these earphones as they were very comfortable in your ear, the earphone rubber parts are clearly labelled small, medium and large and the earphones are clearly labelled left and right. Also, they came with a plastic bit that you use to wrap the earphone cord around to shorten the cable length - something my previous Sony earphones did not have - and something that I definitely needed! So far, so good, as these earphones looked the part.
However, I am disappointed with the noise-cancelling part of the headphones - especially since this was the main feature I wanted from my headphones. When I first tested the headphones I didn't notice any change and I could still easily hear people talking and the noise of the tv. I thought that they were faulty and was about to send them back! But when I tested them against the noise of a stereo, I distinctly noticed that the stereo noise was reduced when the noise-cancelling feature was turned on. I use them on the underground everyday and they do block out most of the train noise and most of the voices, but they are not as effective at noise-cancelling as my previous Sony earphones. I find that I have to have the volume up higher than what I did previously with my old earphones, as this is the most effective way to ensure that I can still hear my music above the other noises of the underground etc. The noise-cancelling feature does work though as the volume is not up nearly as loud as it would be without the noise-cancelling headphones. I'm just disappointed that they are not as good as previous Sony noise-cancelling headphones, but I'm not sure there are many other Sony options at the moment.