Just bought a Sena 20s dual pack yesterday. Didn't get a chance to really try it out because we had heavy rains in my area yesterday. The Mrs. and I played around with the intercom, music and phone functions a bit in the house and it works really well. I'm looking forward to trying it out on the road.
Operation is pretty easy, although it will take a bit of use to used to all the functions. I'll provide further impressions once I've gotten a chance to fully try it out under riding conditions.