Plantronics® Voyager™ 520 Bluetooth® Mobile Headset

Pros: excellent sound quality, background noise not a problem, over ear hook easy to work with
Cons: discomfort

This is a good headset, but the hard rubber tip that inserts into your ear becomes uncomfortable after a while. If you can get by the discomfort, this is easier to to hear when taking calls.
The sound quality outdoes other headsets and much better than the Motorola H700 that I had before.
The noise cancelling feature is great and with a swivel on the headset hook that fits over the ear, I like it much better than the H700 which I had to disconnect and reconnect for the other ear.
The sleep mode is nice, but does create some problems when trying to call out.