I tried one other pair of Bluetooth earbuds from another site before purchasing these. The other pair would not stay in my ears and didn't work well, so I sent them back. When I bought these, there were no reviews out yet since they were just released, so I took a shot, based on the JVC reputation. I have had them for about 3 weeks now, and I have not been disappointed!
These things will not fall out of my ears, and they are comfortable. As another reviewer mentioned, definitely try both sets of covers because the set that came on it were uncomfortable after a while, but after changing to the other size, they haven't bothered me a bit. Connection is easy with my iPhone, and it sounds great! I have not tried using it with phone calls, so I can't speak to that ability.
The only small complaints I have are the lack of bass, and I wish that the cord wasn't so stiff. The cord is angled straight down out of the bottom of the earbuds, and sometimes the cord catches my shoulder and pushes the earbud a bit. I feel like if the cord was angled back, coming out of the earbud, or if the cord was not as "springy", it wouldn't do that. It's just a minor annoyance and not enough to dock it a star.
Overall, I am very pleased with my purchase, and I would recommend these highly!