I bought one of these over a year and a half ago, and used it almost daily with my Panasonic mp3 player. Unfortunately the right earpiece gave up the other day for no apparent reason, but as I've been so pleased with them, I've immediately replaced them. It's easy to forget how good they are until you're forced to use something else.
Here's some comments from one who's used them a lot:
(1) They are comfortable. I used to have some small folding Sony in-ear headphones which made my ears sore after an hour or so. I can wear the MDR-EX71SL all day without a problem.
(2) They block out outside sound well. The earpiece fits snuggly into the ear and not just perched on the outside. This effectively seals the ear from outside noise. A side-effect is that the sound pressure *inside* the ear from the earpiece also can't escape, which means that too much bass can be a bit brutal!
(3) They are *not* built badly, but are a bit flimsy, particularly around the junction of the individual earpiece leads. You do therefore need to treat them with respect. When I put them away, I always wind the lead up around my fingers and make sure that the leads from this junction are wrapped in their natural direction i.e. in opposite directions, so the leads don't kink at the joint. After a year and a half of constant use, this treatment meant that there was no wear/tear/kinking etc showing at all.








