Move air, not bits
First, I should say I've never played thru any kind of Leslie or "spinning speaker thingie" before. Up to now, it's been all sims. So I can't say this is just like a real Leslie, better than this model or not as good as that one. But for those of you wondering, it *is* better to move air than to move bits. I played it with my band for the first time last Saturday, and they really dug it, including the guy we were trying out on guitar (who we've asked to join us based on his performance that day). It was really cool, and even the recordings picked up the effect bouncing around the room (I record every jam with a stereo pair so we can listen back to what we did as well as find undiscovered gems instead of losing them to the ether).
The Pro-3X was enough to fill our small "studio" room against the drummer, bass, and guitar player. The way my amp is set up, the Pro-3X is about at ear level when I'm sitting down. My right ear gets the brunt of it, which I do have to be careful about. It can be piercing!
Providing the organ tone was my Roland VK-7. What was nice was that when you Bypass the rotary sim built-in the VK-7, you also bypass the amp model in the VK-7 as well (this only works if the amp model is Type I or Type II). This allows you to use the V-FET circuit in the Pro-3X to provide the overdrive. Combined with an expression pedal plugged into the VK-7, I was able to nicely control volume that went into overdrive as I pushed into the full range of the pedal and get some nice biting organ tones when I needed them.
So far, so good. I am very happy with it.
I should mention that I did have a weird glitch setting it up and moving it around shortly after it arrived. I had set it up in one location, and decided to move it to another. When I did that, I plugged the cable for the low end into Mix instead of Sim accidentally. For those that don't know, Sim gives just the low end rotor sim, while Mix gives you a controllable mix of low end and the miced real upper rotor. This can be used to send the complete signal to a PA or house mix, for example. So I moved the plug from Mix to Sim, and got nothing out of it, no static, not intermittent, nothing except hum. I played around with it, switching the plug back and forth between the two jacks, trying another cable (the cable I was using was brand new), running the output through my mixer instead of directly to one of my amp channels, etc. Suddenly, plugging back into Sim, it worked. A bit more playing with it and it came and went, but then it worked and has continued to work since. At this point, I'm happy to say it is working, and speaking with the guys at Motion Sound, they did not know what the issue was, as there is no switch or contact like that in the jack nor any setting that would disable the Sim output. I will call them while it is happening if it happens again.
In summary, if you are using a sim built into your clone, or are considering moving air for any reason, you owe it to yourself to check this or something like it out. Just remember that some boards may have the Leslie effect in the samples themselves, and in that case, you'd be running the Leslie effect through the rotary speaker, which you probably don't want to do. But, if you can bypass the rotary effect, then you will find there is nothing like using a real rotary.