First off, the sound quality is above average. Coming from a very basic Jabra BT headset that came free with my old phone, I can assure you, this product's clarity is above average. It's not the sleekest sexiest headset out there, it's kind of chunky and boxy, but it works well and charges quickly. The battery level indicator is nice touch. Add the headphones, and the sound is very very good. Not audiophile good, but great when paired with the convenience of listening to music without a direct wired connection to the player (in my case, a Motorola Droid). I leave my phone on my desk and wander about 35 feet before losing the signal, but this may be a function of the Droid itself rather than the headset. I will say, it is strange the way the BT headset has to hang around your neck lanyard-style when using headphones. There's really no good way to conceal it since, again, it's a boxy unit. It just hangs there looking odd.
The only performance issue I've noticed, and this might be endemic to all stereo-capable BT devices, is that when I pause music playback and switch around between apps, when I resume the music, the audio signal is trapped in a kind of stuttering feedback loop. The only cure is to turn off the BT headset, and then power it back up, then it's fine. It's like the signal needs to reset. I haven't experienced this when incoming calls pause the audio playback, so it's not a big deal.
I really do like this package, particularly because I can listen to talk radio in mono through the BT headset without headphones during boring meetings, and nobody is the wiser ;-). I am concerned about what happens in the future if/when the headphones give out because the connector is very specific to the BT headset, and is not something you're likely to find a replacement for at your local box store. I'm sure it's a special order part. So I'll be careful with these. If you're looking for a way to enjoy music wirelessly through your phone, and get a good BT headset at the same time, here you go, enjoy!