I've been a Sena SMH10 user for a couple of years and really like them. Sena has kept their firmware upgrades coming out for these units on a regular basis. If you are shopping for a comm unit, be sure to checkout the new Sena 20S - it does it all. The unit is not shipping yet, but distributors like Revzilla say that they expect to fill pre-orders in the first week of June. The 20S owners manual is now on-line, so download a copy and check it out before you buy.

EDIT:
A description of the device can be found at: http://www.sena.com/product/intercoms/20s/ and the promo page: http://www.sena.com/promo/20s

I recommend taking a look at it - the device has the most advanced feature set I've seen.
EDIT End:

 

I'm another satisfied SENA SMH-10 user. This is third year for wife and I. Works like a charm. Has good battery life, easy to use with gloves. Intercom is nice and clear. I also have it paired with my Zumo - works great over Bluetooth so I can hear the GPS turn-by-turn instructions and listen to music in my FF helmet speakers.

 

Love Sena. In fact the Sena SMH10 can now communicate with other bluetooth branded headsets with the latest software update.

I'm not aware of any of the other brands that have that level of interconnectivity.

 

I have the SMH10R. Very small footprint. Detachable battery which I hid inside the helmet. The sound is surprisingly good for both speaking and listening. I use for phone and occasional music. Just take your time and really think through the install. Mine is on a HJC RPHA10. The interior padding is detachable making the job very easy. Only one very small hole for the wiring harness. BUT, heavy gloves are a hassle for anything but answering the phone.

 

thanks for all the feed back. When looking at the 10 and 10r it seemed the 10 looked a little balky on the side of the helmet but had more battery life and easier access to controls. 10r seemed really slim and compact thus probably giving up batt. life. I use my zumo 665 to listen to sirius XM radio. will I be able to pair that to the sena to listen to music? thanks

 

It only looks bulky in pictures.

 

I use the scala rider pro when riding with the wife. Easy setup and works over almost 1/2 mile. Can also use to connect to phone to run music, nav and take calls (I disabled the calls as I don't need nor want to deal with a call when riding). Had it for over a year without problems.

 

Yes the smh10 will pair with the zumo. get the full size smh10. better battery, better controls. Who cares what it looks like, you cant see it when its on your head.

The Bell Mag 9 helmet has a version that is built around The SMH 10. it sits in a recessed cavity on the helmet.