I’ve been researching Tuscany for our September trip next year. Not sure if a stop to Bagno Vignoni is worthwhile. It seems there are little or no access to free thermal pools. I would like advice from people that have visited and what their opinions are. Underwhelming? or worth a trip. We already have so many places to go in Tuscany and were thinking of driving to Saturn’s Thermal pools which are free & beautiful ur so I hear! 
Any thoughts or opinions are greatly appreciated! 
Thanks 
Charlene 
In October 2023, I went to Tuscany and drove to three thermal pools.
My account is in this thread: https://community.ricksteves.com/travel-forum/italy/hot-springs-in-tuscany-82fc53ff-87eb-4b52-b688-6510a5f9466d
In a nutshell: Bagno Vignoni is beautiful and worth a stop, if only for a bite, but the free hot spring by the hill is lukewarm at best and a bit slimy. The experience was far better at Bagni San Filippo nearby, at the "Fosso Bianco". Have some cash for the nominal entrance fee.
If you are based in e.g. Pienza, all of this is very close.
Saturnia was way too far from my base in Poggibonsi, I did not consider it.
We have visited Bagno Vignoni a few times (skipped on our recent stay in Tuscany)
It’s a beautiful spot and worth it just for that
It depends on where you are staying.
Bagno Vignoni and San Filippo are only 20-25 min away from each other, basically both in the Val D’Orcia. I think the latter are nicer.
Saturnia is at least 1,5 hours drive away from the Val D’Orcia. But if your travels take you to Maremma, then Saturnia makes sense.