To be honest I don't think the BT2 feature is this particular headsets main selling point - it was a nice bonus because as this feature becomes useful and phones start to have it included then you are already there.
Forwards compatability etc.
The main features that interested me were from a review that I downloaded a while ago:
"Using Digital Signal Processing, the HBH-610 is capable of some advanced sound balancing, bringing the a promise of excellent clarity to both caller and recipient.
The DSP monitors the volume on the headset and will automatically increase or decrease, should the background noise rise/fall, or the volume of the signal sent by the second party change.
This volume change is almost instant - taking less than a second per adjustment. The echo balancing is great, in car, the reverb and subliminal noise are dulled down, making for a far clearer signal.
In the office, the random shouting still comes through, but any regular background noise is detected and accounted for."
The 6.5hrs talktime and 300hrs standby were also rather appealing.