N103 - fits me and my wife fine. Bluetooth and audio sounds great. The internal sunglass works very well.Volume range is good. Nolan has cables for the LT intercom / music, and NAV III
On the bad side, its noisy, very noisy. The airflow is not great, even with the LT window all the way down. Audio is good. But if you turn on the helmet before the music source, the helmet chooses mono over stereo. What lame brain chose that default. Left ear only.
If you broadcast music over BT to a passenger, the gets mono, but at least in both cards.
NAV III over wire is great. Both hear and both get phone service NAV III over BT is terrible. The driver hears everything, but the passenger gets only alert beeps. Think about the fit that the NAV III has when you miss a turn or get on a road it does not have.
I do not know, but I have heard the N104 is less noisy and has a new rev. of Bluetooth.
Bill