I had the sticky keys problem with my first board. The SP4 is not really designed for sound creation. For deep editing, I assume you'd have to create and tweak your sounds on a PC3, and then port them over. Still, it sounded fine, and the ABC organ acquitted itself very well as a Hammond substitute. I would hazard a guess that the electronics are not as high-end as the PC3 range, as it didn't quite have the 'sparkle' that you get with that engine, but it may also be to do with the reduced number of effects blocks. However, when I downloaded the extra sounds from Kurzweil, it became much more interesting. Sounds are a matter of personal preference, but I was slightly disappointed with the out-of-the-box selection. You can hook up a drawbar substitute to it (such as the Ocean Beach DB-1) which hugely expands its potential. It is so straightforward to use, which makes it great for live performance. The action works reasonably well for both piano and organ (obviously not perfect for either).
