My spouse and I are leaving soon for a week in Austria (along with other destinations). A very long time ago, we spent our honeymoon in Austria. On this current trip, we will spend some time in the mountains, then Salzburg, then one night in St. Wolfgang before heading to Vienna - all places we stayed on our honeymoon. We are debating whether or not to visit Hallstatt, another honeymoon location, and which we have good memories of, on our way to Vienna. I have heard that Hallstatt is now overfull of tourists, though I would like to think there will be fewer of them at the end of September.
We're debating - revisit a lovely but touristed village, or keep our memories pristine, skip Hallstatt and plan to stop at other lovely villages on our drive to Vienna? What would you do?

We stayed there a few years ago. The setting on the lake is striking but people working in restaurants, our accommodation, we found really unwelcoming. I wouldn't recommend it at all.

I'd personally give it a pass - it just won't be as you remembered. We visited one year in December and it was still very busy. It's an Asian tourist magnet and I feel for the people who live there.

I would also give it a pass. We lived in Austria for many years and spent a June overnight in Hallstatt; the most enjoyable part of our stay was the late afternoon (after the day trippers left) and the following early morning (before the day trippers arrived).

If you're driving between the Salzkammergut and Vienna, Steyr, Weißenkirchen, Durnstein, St. Michael's (excellent stop for lunch), and Melk would make for lovely village stops. Depending on when in September you'll be there you might catch one of the autumnal wine festivals, as well.