The Leslie 22H is a speaker cabinet that's specifically made for organs. I've used the 22H with a B3 organ at the last studio that I worked at before the one I'm currently at. There isn't too much that sets this Leslie apart when compared to the other top tier Leslies, but this is indeed as good a Leslie as you'll find. Like all Leslie speaker cabinets, it's got the rotating tweeter which gives the organ it's signature sound...
Once the Leslie 22H is set up, there's nothing that you'll need to do in order to control it that's directly on the Leslie. You'll control the rotating tweeter with a control panel that's on the Hammond organ itself. It has a special cable that connects the Leslie and the organ, but once it's set up you won't need to do much with it.
There's really nothing like the sound of a B3 organ through a Leslie speaker cabinet, and the Leslie 22H sounds as good as any that I've used. I've actually done the bulk of my Hammond B3 recordings using this Leslie since I worked at the studio that had it for quite some time. I don't have any complaints about it at all, as it really sounds incredible. If you're aware of what a Leslie speaker can do, I think you'll find that the 22H will do the job as well as any.
If you have a Hammond organ of any kind, the Leslie 22H is the perfect speaker cabinet to use with it. In the studio it's a lot fun to use as it has an incredible sound and is especially fun to mic up this large cabinet. I don't know how hard or easy it would be to get a 22H specifically, but most Leslies of this kind are pretty comparable, so it's not the end of the world if you can't get the 22H. The 122 and 147 are also awesome Leslies, but the 22H is the one I've used the most. It's definitely going to be hard to beat the sound of a Hammond organ when paired up with a 22H.