I wasn't necessarily thinking of a direct comparison as such, this is more meant as a general "what you all think?" kind of post.
As for your strict distinction between the two, then as I skimmed through the outline on that site I'm pretty sure I spotted something about the ability in this program to pre-program the chords and then select styles before initiating playback, not all that much unlike the core function of BBox. And I'm pretty sure that the original .sty files in BBox are indeed utilising pretty simple midi chord rules, like slightly different patterns used for major, minor and 7th, just like what you described (not quite sure about this though). They are however obviously different in that they don't seem to actually contain SMF data themselves, unlike the PSR styles, as you rightly point out.
But as I say, I'm more interested if any of you have actually tried this thing or think it's any good for what it's intended for.

Just because you can, doesn't mean you should!
----------------------------------------------------------------------
BBox 2022 Audiophile, Mac Pro Intel, OSX 10.6.8, 800x600 (TV VGA)