Eric,
There was nothing wrong with the SD90 but the SD40 is a module version of the SD7 which I played for nearly 4 years and had several thousand song setup already gig ready. They worked perfectly on the SD40. On the SD90 it would have taken me 6 months of several hours a day to convert them for the SD90. That was the only reason I selected the SD40. By the way, the S90 actually was an awesome module with just about any control for live playing you would want on the panel. I just didn't wish to spend the time again redoing my gig setups.

Deane