Not the same exact sort of town, but people drive right past St. Gilgen, a wildly charming big village on the lake sort of place. It gets used all the time as a movie set. You might feel like you are missing out by not venturing deeper, but St. Gilgen is Salzkammergut to the core.
Or if you want your mind blown by big mountain alpine scenery and a big network of hiking trails, alpine hut with food and drink, and lifts, look toward nearby Gossausee (the lake, not the town of Gossau). It's not centralized, although if you stay in the reasonably priced hotel right on the Gossausee you won't care a lick. And to be fair to the smaller villages of the Gossau valley, they are pretty darned cute.
Lastly there are many interesting old-timey local places, commercial and otherwise, between the bigger cities. Gasthof zum Pfandl's restaurant for instance, just off the highway a couple of kilometers west Bad Ischl, has a very good locals-priced lunch buffet of traditional Austrian fare. There are no English language reviews of this place, and it's full of non-tourist industry locals. The sort of experience where at first you feel out of place but after a you get a few sips into your beer inevitable are invited to chat. The family owns the hotel, restaurant, gas station and repair shop all on the same property, so eating there is akin to scoring great BBQ at a gas station in the south.
All that said Hallstadt is unique, you won't duplicate it. We stayed, and it was nice after the tour busses left, but not necessarily worth it if you can look past the (other) tourists, or if you aren't so captivated by staring at a pretty town for a full day. Food is kind of hit and miss, and pricey compared to other towns nearby.