I have very limited experience with fully acoustic archtops, but my sense is that in general you don't get as much volume or bass response from them as you do from a dreadnought or other similarly sized folk-style guitar. Also they don't have as much sustain. They do have charm, though, and basswood is a decent tonewood that should improve over time.

My main acoustic since 1985 has been a Fender F265C which was made in Japan. My only gripe with it for a long time was the action. That was somewhat mitigated by the fact that over time it has gotten better and better sounding. These old MIJ Fender accoustics used good tonewoods. Mine has a solid spruce top and rosewood back and sides, and it's really well constructed. It seems true that the sound gets sweeter as the guitar ages. A while back the nut sort of disintegrated and I installed a new one. That led to doing a full setup and it has made a world of difference. Still thinking about doing a bit more work on the bridge, but even as is, it's easier on my fretting hand. If you like the way yours sounds, I would recommend doing a new setup on it. It may be that you can get it to play the way it sounds.

The nice thing about these old Japanese Fender acoustics is that some are really well constructed and good sounding, but also not valuable enough to keep you from working on them yourself. I did get it a better case, tho, when I realized what it would cost me to replace it with one that sounds as good and plays as well ;-)

With regard to the archtop, when I have seen people adjusting the action on flat-top acoustics they generally shave a bit off the bottom of the saddle to lower the action rather than slotting. Not sure what difference it makes, and your bridge is different than a typical flattop saddle. Tune-o-matics are often slotted, and it's about the only way of adjusting the height of the inner strings. I don't know if any of this makes a difference...other than that I should do more reading ;-)