Bomb Factory's Voce Spin is one of two plug-ins that come as the Voce Bundle. The other plug-in in the bundle is the Chorus/Vibrato, with this one being the slightly simpler of the two. Voce Spin is essentially a virtual Leslie rotating speaker. I've got this bundle at home and have also used it on a number of other Pro Tools HD systems. The make up of the plug-in really couldn't be any easier to control, as it simply has two settings to work with. It looks just like the switch on a Hammond organ that will control the Leslie effect, with this one just having two settings for chorale and tremolo, which are essentially just two different rotating speaker sounds. That's all there is to using the plug-in, making it possibly the easiest one ever, so no manual is necessary.
Right now I'm running the Bomb Factory Voce Spin plug-in on my Pro Tools 9 based system at home. I run everything on a Mac Book Pro laptop that has 4 GB of RAM and a 2.2 Ghz Intel Core 2 Duo processor, while I run Pro Tools 9 with a Digi 002R audio interface. I also monitor with a set of ADAM A7's. This system has been more than enough to run Voce Spin and the other Chorus/Vibrato plug-in included in the bundle. These are really low processing power guzzling plug-ins.
Bomb Factory's Voce Spin is a great sounding Leslie emulation and is awesome to have in your DAW at all times. I don't use this on nearly every session, but when I do need it, it's a quick and easy way to get a nice Leslie sound. I like it because it allows me to use this sound for things other than an organ, which I'd be limited to if I was using a real Leslie speaker. For this reason I find myself using Voce Spin on things like guitars, vocals, and everything else in between. It's really a damn good Leslie emulation and while it's nice that it's simple, I guess having a bit more control wouldn't be terrible. The Voce bundle is extremely cheap and definitely worth looking into if you love the Leslie sound like I do.