I just lost my Bluetooth headset in JFK (switching from Emirates to painfully incompetent Delta/ComAir flight to Boston yesterday). I use a Blackberry 7100t and will likely switch soon to a Blackberry Pearl. What are the highest quality bluetooth headsets? Sound quality is obviously the most important criterion. Does Digital Signal Processing really improve performance? Signal volume -- I gather that a lot of Motorola models are just not loud enough. Any other criteria that you use (e.g., comfortable fit, battery life)?

Which headsets do you like best?