A local music store had what he says is a 512ce in stock. Having never touched or played a 12 series (grand concert) because there aren't any in the stores around here, I went in today and played this one. The bottom line is that I liked it.....a lot. I felt the tones were almost consistent across all six strings; if anything, the low E string might have been a little less prominent than the other strings but that is likely due to the smaller body size. The action was very nice even though not quite set up for my arbitrary tastes! (Now I want to try a 612, 712, and 812 but there are none to be found right now. )
However, this one had a mahogany back and sides (check), but a spruce top (not?)....couldn't tell if it was Sitka or Englemann but probably the former. In looking at the Taylor site just now, a spruce top on a 512ce is not a listed option. It appears that the only combo available on the 512ce is mahogany/cedar. He didn't have that combo in the store, nor any other 12 series Taylors.
So, what was I looking at? What gives? Could this be a discontinued combination? The store's tag on it was ignored by me and I didn't think to question the top wood until I got home and got on Taylor's site.