...not bad, actually. My wife had seen an ad for one of these in a magazine (an in-flight mag, maybe) and wanted to get one--she doesn't like wearing a headset, and wanted to get a reliable speakerphone solution ahead of the new CA law that takes effect on 7/1 (banning hand-held cellphone conversations while driving). She actually has a built-in BT speakerphone in one of our cars, but has
two phones and wants to have them both paired at once to separate devices, not to mention having a portable solution for when she's in the other car, in a rental car, etc.
The local mall kiosk had one for $149.99

, but Amazon had them for less than half that price--$146 for two units, shipped to arrive in 3 days (actually came in 1 day). I got them on Monday and have been using one on my commute into LA everyday.
Setup and pairing with my BlackBerry was easy, though thus far the phone and speakerphone don't seem to want to connect automatically--I have to go connect them manually every time (maybe I need to reread the manual). Sound quality is good--can be very loud, actually. One drawback to this not being a built-in unit is that the radio in my car doesn't mute when the phone is in use (so I just turn it off, not difficult). It attaches to the sun visor by means of a magnetic clip, so that the clip can stay on the visor and the unit detached and put into the glovebox when not in use. There's also a clip to attach it to the dashboard vent, if you don't want it overhead on the visor.
I give it ^^^^ out of 5.