rotor speeds, spin up/down times, motor noise, equalization, etc. I am currently pairing it with Acousticsamples B-5 organ V3, which to me sounds better than IK Multimedia’s B-3X with the built-in Leslie simulator. It’s also less resource intensive and with a more responsive UI than B-3X. At 50 bucks, I think the rotary plugin alone is more than worth the money and you get the organ thrown in.