Let's just get down to it.  If you are reading this review because you are shopping for a new Bluetooth headset, just go ahead and finishing reading the next couple sentences and then you can do what I did... buy the Plantronics Voyager 510 at Amazon (for under $45.00 as of this review).  I own 10 different headsets and have used them all to make hundreds of calls in all types of environments, and since we can only really rate products on a curve, there is currently no better choice at this time (things will no doubt change one day).  It is the most stable, the most ergonomic, the most static free (there is no such thing as a completely static free wireless product), the most efficient with it's battery usage, most comfortable (a somewhat subjective attribute), the most bang for the buck, the most satisfying to use, and the most 5 star rated Bluetooth Headset money can buy.  I can only really complain about one thing... a very sensitive microphone that will pick up wind noise in moderately windy conditions (in spite of the noise cancelling technology), but this is certainly true with every headset that I have used and probably true with ALL headsets when you come down to it.