On the SA organs, the Leslie is on the mod wheel and is not removable, and same goes for SA Rock Rotary, which is a lot the same as Jazz Rotary, except for a tad less perc, and a bit more overdrive/distortion, although you can adjust the latter(and take it off) for both organs.

I rarely played the organ sounds in the S900...they just weren't "Hammondy" enough.

With the S910, I'm more encouraged to use that sound more often.

If I was using it exclusively as an organ, I'd miss the drawbars and the abilty to shade the sound...on an arranger, I don't find that as important.

You know, one of the reasons I was going to get a Roland arranger, is that they have great organ sounds; even the E-60/50 are very, very good, although they don't have the drawbars like on the G70.

With the S910, I don't need to go there...the organ sounds are finally good enough...nope, they aren't as flexible as I'd like, but they have "the sound".

The percussion is polyphonic, so a bit less realism there, but, overall, I'm very pleased Yamaha finally caught up to Roland, at least in the preset organ dept.

The S910's drawbar organ section, is still the same as on the S900, and less inspiring, and the inability to add distortion/overdrive with the Leslie effect is a pain...it's on the Tyros3(and I believe the T2 as well)...they have another effects block the S-series lacks.

Several S910 users have told me they like playing the instrument more than they did the S900...part of it for me, at least, was the enhanced organ sounds....again, I repeat what I've said many times...the S910 is what the S900 should have been.

Realistically, I'm afraid I'll never be gigging with a B-3 again, so the S910 fits my plan just fine... and, it's only 400 lbs lighter.