Here's the way it works:
Steel Beasts Pro PE is the new, revised graphics engine, plus multiple crewable vehicles (Steel Beasts 1 had just M1 and Leo2) plus other stuff. It's $125 US and is going on sale next week.
Steel Beasts Pro is the same game, but with enhanced AAR features, "God room" etc. That is just for sale to military customers.
Steel Beasts 2 is a forthcoming "gamer-fied" version of Steel Beasts Pro PE that will have some degree of realism stripped out to make it easier for the boy gamer crowd to deal with. It's also by no means a done deal, as no work has been started on it.
From forum discussions with the developers, it seems that Pro and ProPE are the same codebase, with Pro having extra modules. It seems likely, based on what they have been saying, that there will be a series of enhancement packs released periodically for Pro PE as Pro (military) customers get their requested features added.
I have Steel Beasts 1, and it is very good, the prime drawback being that it only runs in 640X480 and that you only get M1A1 and Leo2A3. Gunnery realism is top-notch, down to having to index ammunition, select first-return or last-return on the LRF, dump lead using the palm switches, etc etc. With Pro PE adding Leo1 and LAV-25 to the crewable vehicles, it looks like we'll be able to get gunnery practice in Canadian vehicles on virtual Canadian training areas.
I also found a company that makes USB controllers based on M1 and Leo2 "Cadillacs", but they are $1000 each!
The game can be networked, and crews can play stations. It would be very easy to build a poor man's SIMNET around this game.
In fact, I used Steel Beasts 1 to demonstrate to an Armoured Recce DP1 course how thermal sights, gun stabilization, laser rangefinding, ballistic superelevation, and dynamic lead combined to allow a modern MBT to shoot and hit a moving target while itself on the move in less than 7 seconds from time of acquisition. It worked.
DG