I have had this for a few months and think its great, using it with iphone 3GS.
Although the mic isn't the best it is better quality than other well known car hands free kits which I've had.
music quality over Bluetooth is spot on and can't tell any difference to my CD quality. one down side is you cant skip back a track only do next, pause and voice command (perfect for people lucky enough to have a 4S with siri. it does work with the old style voice command that my 3GS has).
rating 4/5 due to the mic quality although its the best i've come across! It could be due to the fact I have the mic placed down near my arm rest. placed down their for easy use of changing song while driving.