Everything is fine except for the sound quality. If you listen to them straight out of the box they're pretty bad, but you can adjust them using equalizer software to make them sound bearable. The build quality seems decent for the price, and they are quite comfortable in the ear, as well as firm once you find the right sized earbud (you get a wide range to choose from in the box) meaning once they're in they don't move around so that helps immensely when moving about. Additionally, the noise isolation is great so the sounds around you won't be intruding on your listening experience, making them especially ideal in loud environments. So despite the sub-optimal audio quality, they excel in just about every other area making them decent overall, but it's a shame that they just don't sound a bit better to make them really worth the $30 over wired alternatives out there in the same price range.
So do I recommend them? Well...
For general users: At the moment I'd recommend a decent pair of wired earphones over this, you can pick up a pair with great audio quality for the same price or even cheaper. If you really insist on wireless, maybe look for other deals before resorting to this, which won't be the worst "last choice" option out there, but surely there are better ones to pick from if you search for them.
For the sporty type: All that being said, since they're marketed for sports use, which is reflected by the build and design, if this is what you're buying them for definitely go for it. The wireless feature makes all the difference in this aspect and so does the great firmness of it. You can shake your head around violently and these thing still won't budge at all once they're in your ears, which is fantastic. Hell, they're the only earphones I've ever worn that don't move out of place when I move my jaws around while eating, out of half a dozen earphones these are the only to pass that test. They beat my $100 Audio-technicas in this regard, so if you need something for when you're out running, cycling or doing any other sort of physically intensive activity, this was made for you.