Horrible value for money: booked a superior room for EUR 200+ / night but was just a tiny regular room with an angled partial view of the main square, which apparently was enough to justify the "superior" classification. Overpriced, especially considering this is a 3* hotel.
Disappointing spa / thermal bath: price includes access to spa and thermal pool, which I thought could somewhat justify the high room price. However, there are only two ~4x4m sterile, uncosy, indoor pools (only one with thermal water, and not even 100% sure about that) and a steam room. We left after 20mins. Given people come to Bagno Vignoni solely for the thermal baths, the offering is underwhelming to say the least - most ski resort hotels have better spa / wellness facilities.
Location: this is their money maker. Hotel is in the main square, couldn't be better. Parking is nearby and free.
Service: neutral experience with welcome, check-in and reception in general. Breakfast was good with a decent range of both savory and sweet items.
Summary: I do not recommend this hotel. Price-to-quality ratio is simply not worth it.