Jumping in a bit late, since I just saw this thread.
I use the Sena SMH10 system in all my helmets, with several modules all paired to my Android phone. I have a charging port in the trunk of the Norge, so I can swap from one module to another on Ironbutt rides. I wear custom-fitted earplugs on the highway, but the Senas have enough punch to still be listenable even with the plugs in place. While not audiophile quality, it is good enough. My phone has most of my music library on board, thanks to a 64GB memory card; I use MP3 with SBR compression, since the sound quality loss is not noticeable on the bike - FLAC lossless is the master format at home.
I can appreciate the point that it's nice to just ride and listen to the experience without additional content - but for me, particularly on endurance rides, music helps keep me alert and responsive. The changes in rhythm, melody and style are particularly helpful in the big empty spaces we have to cross out west...