Personally, I think the S910 is what the S900 should have been all along.

Definitely a nice jump up for PSR-3000/S700 owners; not so much for S900 users.

My sample account S900 goes back to Yamaha when the S910 arrives sometime next month, so I'll be looking forward to trying it out.
It has two of my favorite organ sounds from the Tyros3; SA Rock Rotary and SA Jazz Rotary...both are excellent B-3 sims.

The S910 will be only 400 lbs lighter than my old B-3.