Hey Couch, for me the choice is a couple of things. As the SHM10 & 10R offer similar performance, the final decision comes to size & style. I Locke the idea of been able to put my lid straight into the panniers without having to pull off the unit. I generally ride without a topbox (unless it has the pups in it), so the lack of room can be an issue.
From everything I've read, the 10R isn't difficult to learn to use the main functions, so this will sort out 90% of my needs, functionality wise.
I also didn't really like the look of the mounting bracket for the SMH10, it seems to sit a fair way down under the lid, which to me, seems like it would catch on my jacket collar every time I turn my head. I haven't been able to see if there is a different mount (similar to the interphone units) that would suit me.
I don't like the interphone unit, and Sena seems to be the leader of the bluetooth pack, which lead me to choose the 10R.
Cheers!
Nate