I've got a new RT with the BlueTooth option. I would like to purchase a bluetooth set for our helmets (wife and I ride 2 up most of the time). I see the BMW set is $900. The Sena 10 is only $399 for the pair but on the Sierra BMW site they say the Sena will only recieve the audio in one helmet at a time. Stating the 2nd helmet has to use a different audio source. Can anyone advise or does anyone have experience with the system?