Iris,
They seem awfully proud of their products ($$$). Have you considered going with Sena BT headsets and maybe one of their BT hubs for handling the legacy devices?
Josie and I are still rockin' the wired Starcom1 for intercom and headsets, and I've yet to have to replace a headset. But I do realize that we are sadly behind the times in that regard. I also have a Sena SMH10-11 headset, and a Sena SM-10 multimedia BT hub that I use on the bikes when riding solo. I may eventually buy a second SMH10-11 and finally ditch the old Starcom, but you know... when it ain't broke (yet), why fix it?
The Sena SMH10's are very stable at this point, possibly because they are no longer their current "state of the art" product? I cannot complain about their performance in any way. I know you will be interested in the bike to bike performance, but I have not tested them in that way at all.
Anyway, it is another possibility for you guys to consider.
PS - RFR!!
edit the SMH10 dash 11 is the one with an independently positionable boom microphone OR a velcro-in spot mike in your helmet chin bar. It makes installing it correctly much easier than the all-in-one regular SMH10 with the integrated boom microphone. Worth noting as it doesn't cost you much more up front.