I have finished the installation of the Edset mic-splitter and it works very well. I use it to listen to the GPS (Zumo), MP3 and phone through my headset. Just in case someone ask, when using the phone I pull over. Its a good set up because I can see who's calling and if want to speak to the caller I pull over and I don't need to remove my helmet. Once I am done I just keep going.
Gaetan