Hello Dan,
I am very happy for you and your new descoveries. The funny thing is you always have all good news and never any bad news about sd1. Maybe because you are selling them and it would be bad for sales. I am not saying it is a bad keyboard, but it is not a finished product. When I am playing my custome style which consist of Fusion drum set in drum1, Rock bass, Gipsy guitar in chord1, wave drum loop in drum2 and playing melody,having 2 or 3 keys down at the same time, some of my chord parts like the drum or the bass disappear on me. It seems to me that the keyboard is running out of notes. I have more instruments recorded in my very old korg i3. I am using layered sounds in right hand and the i3 handles it fine which has only 32 note polyphony. Sd1 is supposed to be 64 note polyphony.
I am just a honest user of the sd1 keyboard, not a salesman.