I bought a pair of these to replace the earphones that came with my iPhone 4, as I lost them. I wanted a pair of earphones that were comfy, had excellent sound quality and had a remote that could do all of the things the Apple earphones could do. After doing plenty of research I opted for a pair of these, and alas, I was not disappointed.
First of all, I would like to point out (as it is not made clear in the product description) that these earphones DO have a microphone built in to the back of the remote, to enable hands-free calling. It may not be as good as the microphone on the Apple earphones and the callers voice does sound a little tinny and distant in comparison, but I haven't had any serious problems with calls so far.
The remote operates just like the supplied Apple iPhone 4 earphones. It has an up/down volume control and a triple function middle button - 1 click: pause/play/answer call/hang up. 2 clicks: skip to next track. 3 clicks: back to start of track/previous track. Other reviewers have noted that the middle button is a little stiff during first use, and I agree, but it loosened up within the first day.
These earphones are supplied with really comfy, soft buds of three different sizes and are easy enough to change, and do not come off easily at all once they're on. The buds are also quite effective at blocking out some unwanted sounds from your surroundings (if you've chosen the correct size buds for your ears). A Sony branded pouch is also supplied, but I don't use it as I reckon the earphones will still get tangled inside the pouch - I use a more compact case from an old Philips set, which has a zip and a small Velcro strap inside to keeps the phones separate from the wire (hence no tangling!). Sony also throws in a clever little gadget that allows you to neaten up any excess cord you may have flapping about. I've only just started making use of it recently and like it a lot. The cord leading to the phones are symmetrical and can also be neatened up with the tiny attached sliding clip.
The sound quality is very good indeed for the price of the earphones. The sounds is very well balanced and the low and high frequencies can be heard clearly. It is almost worth re-importing your music to a higher bit rate to make best use of the detail that these earphones can reproduce. My only criticism of the sound is that they lack resonance. For instance, the sound of plucked string or the strike if a percussion instrument dies quite quickly when compared with other earphones, which is a bit of an issue as I mainly listen to classical and jazz music. But I guess this can be overlooked when you consider the detail that these earphones can deliver. Another minor criticism is that I wished Sony had given these earphones a straight jack instead on a L-shaped jack, but I suppose I can live with that.
All in all, ad excellent set of earphones to buy when replacing the supplied set that are more comfy and sound a lot better!