hoter,
I work for a distributor that carries 6 different models of Bluetooth headset.
The best one will depend on your situation. If you are looking to do 2-up riding you can't beat the
Cardo Scala Rider Teamset it will pair with the bluetooth device you have (phone/GPS) and also act as a full duplex rider passenger intercom. This is done with the included slave unit, what is really cool is that you can conference in the passenger or the passenger can be the one to take the calls and conference you in (which is likely safer)
The Blueant Interphone is a good product becuase it allows a two way full duplex intercom with another Interphone within 500 feet.
There is also a really nice product that we just released called the
Camos/IMC, it does Bluetooth 2.0 which allows for higher transmission rates, and thus stereo bluetooth, so if you ever have any intention of doing music this would be the best headset for you. There is also a model that does intercom. I just started using this one and love it more than the other two, as my phone can stream stereo bluetooth and take calls, plus the speakers on it deliver great bass and treble.
Sorry to overwhelm you, but I have a lot of experience with these, so I thought I'd throw my hat into the ring.
Cheers
