I turn the mic distance knob and it's not affecting my sound at all...

Seriously? It was immediately obvious to me. Perhaps you guys are expecting something more dramatic, but to my ears, it sounds just like it does when you move the mikes from a foot away to 3 inches. Well, there are all the other Leslie sims already mentioned that may be more to your liking.

Don't rush me. I'm playing as slowly as I can!