I have the Sena 10s and the 20s. I prefer the 10s because it is easier to share music with my wife. They screwed up on the 20s IMO because you have to have it set for multi tasking to share music, then if you want intercom you have to damn near yell into the mic for it to lower the sound of the music to hear the intercom. The 10s has a better range than the 20 in real world use. The 20s allows you to communicate with more people if you do large rides. Both of them can use the app that will allow as many people as you want to be on coms with you. The 10s is cheaper. I like how the 20s mounts better. The 20s has better speakers and better noise reduction. The 20s also has a feature that you can dbl tap a button and hear ambient noise because there is a mic on the outside of the unit. That is good for when you want to talk but not take off the helmet.
No matter where you go there you are. - Buckaroo Banzai