I'm another very satisfied J&M user. The unit gives complete control at your fingertips. The PTT trigger is appropriately placed, letting you activate without removing your left hand from the grip. There's even a PTT button for the passenger. Mine's mounted on the left pillion side grip. I use the 3' antenna offered by J&M, albeit mounted on a MCL mount (on the right-hand side).
The auxiliary plug allows me to incorporate my iPod with its 7000+ song library. The auxiliary circuit is great with an amplifier that does a great job of maintaining a good quality signal without notable clipping.
We use the Elite headsets and the sound quality is superb. I'm picky about sound where my music is concerned and I am totally pleased with these. A bit pricey, but well worth it in my opinion. My brother, who has always shunned in-helmet speakers on his Goldwings and Harleys, opting to use the external speakers instead, has now converted to J&M Elites, as he was bowled over by the sound quality.
The intercom works marvelously, always on, without any VOX or PTT issues. You just talk back and forth as if you were sitting in a room together. If you've got music playing you just talk over it, just like you would chat at home over the TV/stereo/etc.
I've now added a Zumo harness which allows incorporation of the Zumo 550. This not only allows me to hear GPS directions in my headset, but also allows me to receive and make phone calls from my Blackberry via the Zumo's Bluetooth telephone feature.
Frankly, the whole thing is just amazing in its seamless incorporation and its functionality. The ONLY complaint I've got is that when I key up to talk on the CB, my passenger cannot hear what I say. Likewise, when she keys up, I cannot hear her either. This is a nuisance, but we've learned to live with it.
Everything J&M is quite pricey, but I believe it's worth every penny.
Steve