Sorry, got busy this weekend and missed your question. I've moved so I don't have access to that Casio any more. They're available in lots of places so try to find one and play with it.
I looked up the unit and it has digital drawbars with percussion and keyclick control. It has 50 organ presets and memory for 100 user presets. I don't remember now how good the leslie effect was except to say I thought the organs sounded pretty good overall and I always listen for that but can't help you with that level of detail. I'm pretty sure if it was a cheesy leslie I would have remembered that. All I was doing was showing the girl basically how it worked not testing it out for myself.
The online user manual doesn't go into the leslie effect either but it says it has full editing of all the DSP effects but it doesn't actually list them or say what that editing is. You have to have one in front of you and see what shows up in the edit screen I guess. In the synth section the manual does talk about full ADSR editing functions so it maybe it is pretty complete as far as rotator ramp speed etc but I can't say for sure. Still for $400 it's not bad at all.

Bob

Biab/RB latest build, Win 11 Pro, Ryzen 5 5600 G, 512 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.