I just played the 2016 322 12 fret last night. I haven't played the 322 12 fret with Sapele back and sides, but I read another review that said the Sapele 322 sounds very similar to the hog-topped GS Mini. Makes sense to me. (I own a hog Mini, and the 322 isn't that much larger.)
The guitar played very nicely, and the blackwood sounded very different from Sapele to me (although the wood looks sort of like Sapele). It's actually sounds closer to rosewood without the chime, or maybe even like koa.
I don't mean this in a bad way (this is the Taylor forum, after all,) but my first impression was that this guitar sounds like a Taylor. It has that signature Taylor sound that you'd instantly recognize in a blind recording.
This guitar came with Elixer HD Lights, and I personally don't like the added tension in the treble strings in this set. This particular guitar needed a setup as well, because it didn't play as nicely as other 12 frets I've played. I tried to ignore both of these things to keep an open mind.
In the end I thought the guitar was nice, but not a must have for me. I was interested in this guitar because of the low price point and the fact that it's a 12 fret grand concert. If this was a first guitar or even a second guitar, I wouldn't hesitate to get it. But for me I'd rather pay the (substantial) difference and get the 712 12 fret, which I think sounds phenomenal.
So all in all the 322 didn't wow me, but that doesn't mean it isn't a fine guitar.
To George's original question, if it came down to the 322 SEB and the 2016 blackwood 322, I'd probably choose the blackwood 2016.