Dave sorry to hear that....the SD7 isn't for everyone...especially with your right hand trigger vocal demands, which btw you are the only person I know who does it that way....lol But I understand your feelings.
Funny how we are all different players with many Different Needs. For example I don't like the sound of the BOSE systems for a few reasons, Fran loves a 20yr old Roland G70, go figure?......I also didn't care for the KORG OS & many of their styles on my Pa3x of which I traded you for the S950 lol the VH isn't that important imo I use it sparingly these days anyway,....we all like what we like, there's nothing wrong with that.
What ever make a player comfy and happy is the right choice for them. For me the SD7 is an amazing unit, but I agree it's not an OOTB arranger Kb, you have to MAKE IT YOUR OWN!!!...if you do your homework setting it up it will definitely serve you well. After watching that S970 demo I'm know I made the right choice with the KETRON SD7...
Have a great day!!