Hi Brett, I have a Matrix 12 that I use with Soundiver. I use soundiver standalone, just as a patch librarian. I think the M12/Xpander SD implementation is very good. I use nuendo to sequence the M12, and I use the lever 1, pedal 1, velocity, and pressure as my controllers for each voice (like if I want to change aspects of the sound during a sequence). I don't find the sysex to be as useful as I'd like, have you tried sysex control of voice params? Lever 2 and pedal 2 unfortunataly are NOT specific to each midi channel voice, do you have this same experience? BTW, if you have any patches you'd like to trade let me know. Randy