After losing my last Plantronics 510 to a "dog incident", I picked up another 510, a Motorola H710 and a Jabra BT8040 and put them to the test head-to-head.  I use a Uniden cordless land-line phone that can pair with a BT headset, and a Palm Centro smartphone.  All three of these phones support multipoint.  The H710 failed to cancel echo (my voice played back to me delayed) on the Uniden phone, and the BT8040 would not pair with the Uniden at all.  All three worked well with the Centro.