I use both, the scala rider bluetooth and in ear buds. The scala bluetooth speakers totaly suck for music but work very well for intercom and cell phone use. My buds are high end but not totally noise cancelling. I can still hear the scala unit (cell phone/intercom) and off the bike conversations with helmet on. Plus they still reduce a lot of wind noise. Of course it's hard to beat a set of in-ear buds for excellet sounding music.
I use this speaker combo with my Sirius radio and MP3 playe. The MP3 player has the best sound reproduction but the Sat. radio can't be beat for variety. I used to use a normal FM/AM radio but hated dealing with the loss of clear signal. My commute is over 65 mi 1-way. It was a total bummer trying keep up with all the signal loss / chanel changes. Sirius solved that instantly without the predictive nature of the MP3 player!
No doubt that music (at high volume) has it's hazards on the bike, but I'll deal with it. It makes my long commute so much more bareable, I'll never go without it! The drone of my motor on a long ride home at night is like a sleeping pill for me. Haward Stern or an audio book keep me awake and make the commute seem a lot shorter. Without audio intertainment, I tend to use the throttle on my Busa to make my long commute seem a lot shorter.