Jabra BT2040 works well enough
Set up and connection to mobile straightforward and seems to work well.
I have not used other bluetooth headsets before, so I cannot compare, but it sits comfortably enough and the earpiece sound is reasonable and speech well understood, as is the sound at the receiving end. I used it in the car with voice-dialling and no communication problems with my old-ish diesel engine running and going at moderate speed.
I am sure there must be better sets around, but at that price it works well enough and will suit my occasional use of the device probably better than a re-chargeable battery set.