How it sounds isn't a big factor at all, SA2 for me is irrelevant, the S-950 is more then enough capable to sound terrific in most situations, as it is ......what I'm hoping for is a better "gig worthy" navigational design, display, VH, inputs, etc...

Not sure that Yamaha would put "gig worthy" improvements on what they market as a home keyboard. What they've got now sells okay, which is why they'll add a couple of features, give it a new model number, and rip people for a new keyboard. Business as usual, Yamaha style.