Ditto to what Don said, ...SD7 is very stable, Display is BIG, BRIGHT and easily readable, The OS is very easy to-operate and very logical in it's execution. You can save changes, edits etc on the fly in live play with no glitches or pauses at all something I couldn't do on my S-950 while playing. Jumping back and forth between Reg style play & Mp3/Smf song play is seamless with just the touch of one button which I really like. Sliders are of top quality built also not those shaky ones on some keyboards...navigation on the SD7 is a players dream & one of my pet peeves when I perform & the SD7 seems to so far addresses this nicely for my needs. As was said before the Voc processor and VH is on par with TC Helicon, sounds really good with excellent tracking. Speakers are the loudest I've heard on an Arranger KB, for those occasions when your in a very small room or small NH scenario the KB alone will cover it all by itself. I'm also getting used to this nice keybed feel as I transition from the featherweight S-950 touch to a more substantial feel with the SD7 it feels more like a Fatar KB. Little things like a speaker on/off switch in back is convenient & 3 front USB ports too. I also like that holding down many of the buttons, or screen Icons will activate popup menus for editing instantly. Playing live on screen you can SEE ALL 4 OTS Sounds for instant access at the touch of the icon in live play also besides all the fills, breaks too.
I'm learning more each day as I play it and set it up.

Stay tuned.