These fit great, and look amazing. The mic and buttons work well, and feel way more solid than most OEM earbud/mic combos.
As far as sound quality, these completely murder stock iPod headphones, and even the more expensive silicone-tipped Apple earbuds. They fit more snugly, and I found myself needing to readjust them MUCH less. I'm sure there are other brands that are louder or more crisp, but none of them look as good as these do.
Like most of the reviews have already said, these DO transmit quite a bit of noise up the wires if they rub against things. For me, that wasn't really a dealbreaker -- iPod at about 75% volume covers it up nicely -- but it's a little bothersome when you're on a phone call. It's not bad enough to make me want to return them, just annoying enough for me to give them 4/5 stars.
Bottom line: When they go on sale, they'll be worth every penny.