Dear Jim,
I also used to have a Leslie cabinet (122) with my Hammond L122R, and desperately try to find something better then what I found on arrangers (I had many Korg flagships before to move to Genos),
I feel that REAL ROTARY is to "weak", almost a Vibrato. ROTARY SPEAKER 1 looks a little better, but still weak. The best I found is a Legacy Rotary, Legacy/Rotary Speaker 5, that has more stereo depth on both slow and fast.
I have to say that Mini Vent is much closer to a real Leslie. I wish Yamaha would do something similar.
Ciao
Angelo