I always admired the SENA headsets, however i may just look for an earpiece, as i really dont want to comunicate with others "girlfriend" while riding, lol
I'll tell ya what, normally, I believe in 'You get what you pay for'. But, last year I got a $100 Amazon Gift card and didn't know what to do with it, so I bought a Shark bluetooth headset (comes in a set of two) for about a hundred bucks.
WOW is all I can say. It's held up, it handles all sorts of weather, it's plenty loud, I can easily hear my music at 80mph+, it's very clear audio to chat with my wife (if you don't need that feature that's fine too). It also works so well with my phone, that when people have called me, they have no idea I'm on the bike. It auto-answers when someone calls so there is no manipulation of the phone or headset.
My friend has a SENA headset, it's very nice. The fit and finish is a little better, and the big volume dial kicks the tiny buttons on mine's butt. However, he has trouble hearing me on the freeway, when he comes in clear as a bell for me. That could be his ears vs mine, but, I'm still QUITE impressed.
It's designed to work with 3/4 or full helmets, but I imagine you could retrofit it if your handy to work with a half helmet or otherwise. I wear a full face though so it just worked out of the box.
Ignore the 'list price'. It's a marketing technique shark does. They never have nor never will sell that product for $500. It's always $100.