I've tried several brands and models of wireless headsets.  The first was the Logitech Mobile Freedom.

PROS: It works great.  Calls are very clear for the people on both ends of the call.  Their windstop technology is awesome, even with the window down in a semi, I was able to carry on a conversation.  8 hrs of talk time is wonderful.  software, pairing and communication with my phone were top notch

CONS: bulky, unattractive, made the back of my ear hurt after a few hours

I went looking for something a little more cool and comfortable.  Jabra BT 250, 500  Motorola  H700, and the HS 850.  I tried all four of these and they were all COOL and all were more comfortable.  Quality and clarity of the are paramount for me so I went back to the FAR superior Mobile Freedom.  I found a smaller model:  Logitech Mobile Traveller has all the pros of its predecessor.  Unfortunately, it also has its cons.  Finally, I purchased the Planetronics Voyager 510

PROS:  Has all the call clarity of the Logitechs, comes with 3 different size ear pcs. to fit any ear.  Very light and comfortable on/in the ear.  I can forget it is in my ear.

CONS: Biggest drawback is short talk time of 5 hrs or less.  The software (call connection) not as smooth as the Logitechs.

My conclusion was to use the Voyager 510 as my every day headset and to keep my Mobile Traveller in my car as an extra