I have tested 6 Bluetooth headsets paired with the 8700 in an everyday working environment for about 4 days each. In real estate I generally make and except around 50 - 80 calls per day. My observations are...
Motorola HS820 - Too much lag time when answering and terminating calls. Loose fit, low volume issues, and static when in conversation. Poor range.
Motorola HS850 - Too much lag time when answering and terminating calls. Loose fit, low volume issues, and static when in conversation. Poor range.
Motorola H500 - Too much lag time when answering and terminating calls. Loose fit, low volume issues, and static when in conversation. Poor range.
Motorola H700 - This headset is super tiny, 1/3 the size of the HS850 and looks sharp. It has a nice fit due to it's weight and size. It is however plagued with problems as well. Volume is better than the HS850 but you have to have it turned to maximum volume and that still isn't very great. The main problem is lots of static while wearing the 8700 on the same side that you are wearing the headset and anywhere more than 5 feet away from it. I was really disappointed with this one's performance, especially at $130.
Plantronics 640 - This is a great headset. Had to keep the volume at half, and had great clarity. Range was about 20 feet before you get any static. You can wear it with the earclip and can easily be worn without it by just inserting the eargel into the ear. This headset would be great for anyone that wears glasses. The case you carry it around in vibrates when a call comes in but the headset tends to fit loosely in it and could easily become lost. I had to return this one because it quit charging, just a defective unit. I think I may pick another one of these up as a secondary headset.
Plantronics 510 - This is the best headset I found for performance with the 8700. It connects and terminates calls perfectly with only a hint of delay. It is surprisingly comfortable being an "over the ear" design and is very light. I have to keep the volume at half and voice clarity is excellent. Range is outstanding, I can leave the 8700 in one room and go three rooms away without any static. That's at least 30 feet with walls obstructing the signal.
I of course returned all the headsets that did not perform to my satisfaction, I don't need all those lying around. I am definitely keeping the Plantronics 510 and as I said above, will probably pick up another Plantronics 640 as a secondary headset. Hope this helps anyone that has the question "which BT headset performs best with the 8700.
Shane
NC