I use J&M CB radio on the ST1300. This includes onboard intercom for rider/pillion. It also integrates my iPod and Zumo - Shoei RF1000 helmets are wired with Elite headsets. Sound quality is superb.
I use Chatterboxes in our off-road helmets for ATV riding. Although I'm pleased with the radio communication and VOX performance, the sound quality of the iPod through the Chatterbox' auxiliary circuit is absolute crap. Honestly, a dime-store transistor radio from the '60's sounds better.
Things are a lot more like they used to be than they are now...