Hello again MrJerome!
I ditto your comments.
Unfortunately, I may need to retire my HS850 with the Ipaq 6315. As you know I have the Treo as well as the XV6700 and can confirm the Motorola HS850 has the same crackle and poor volume with both. It workd great with the IPAQ, however.
I will investigate your Plantronics choice this weekend as the new experience with the XV6700 has kepte me from completely switching over from my IPAQ. As for my wife's Treo, she hates hands free devices because it is a hassle to put on getting tangled in her hair. She just chooses to answer the phones in the car illegally.

The poor quality of her HS850 hasn't helped convert her to hands free either.