Yes the RAM is need to load INS, MSP, and User Live Guitars.

With the RAM expansion, 192MB is not too bad for create and load many new sounds using MSP!

And the advantage of audya to others keyboards (ex: Korg Pa3x) is the Drums in WAV loops (Users Audio Drums) don't need any Memory RAM.

But is sad the users dont can create new drums kits with samples...