Overall this is a really nice addition to the HB stable. I suspect the one I received probably should have been a "B" stock. There are globs of what appears to be epoxy or some other adhesive substance in the sound chamber of the particular guitar I received, but it doesn't seem to be affecting playability. The sound is a bit deader than I expected, but in fairness that could be the ABS body simply doesn't resonate as well with that adhesive in the sound chamber. (I was not able to get a mirror in there to tell conclusively.) Still, this is a really nice guitar. No discoloration on the binding and no fret sprout. All I did was oil up the fretboard a little bit and it seems fine. The fretboard looks great and the frets themselves were highly polished on arrival.
After my initial testing, I did swap out the stock tuners for some locking tuners and roller-type string trees. I did have to adjust the truss rod a little bit as the action was a bit higher than expected. (It was .012 on the bass side and .10 on the treble side.) Once adjusted it dropped into a very playable state. Even with these somewhat minor issues, I am still a solidly loyal HB customer. I think that I just got that one-in-a-million glob of adhesive on mine in the sound cavity as I do not hear of anyone else having this problem.
I plugged it up to a Katana Air amp I have and on the acoustic setting. In both plugged and unplugged states, it sounds good. Again, not quite as resonant as I was expecting, but still really good.
This compares well with my other acoustic and semi-hollow guitars and I believe I will get a fair amount of use out of it. Love the black finish and it just gleams!
Thanks, Thomann. A great product (minus the few comments above.)
Update Nov 23, 2021: After spending quite a bit of time playing with this guitar, I have decided to revise my comments. While the epoxy inside is not visually pleasing, it does not in any way detract from the playability of the instrument. I did a couple of small upgrades (new tuners and shaved a tiny bit off the bottom of the bridge) which dramatically improved its playability. Not everyone is comfortable working on their guitars and I don't recommend this to everyone, but with a few small tweaks these guitars become highly playable and sound great. I would highly recommend this ST-Acoustic to anyone. I have found it to be the guitar I typically pick up when I am going to work on writing music as it is light, easy to play now, and sounds good for my own style of use.