Planning on Tuscany trip late September. Any suggestions on best centralized place to stay? Thank you.
Florence or Siena
Unless you’ll have a car
It depends on how long you plan to stay and what you want to see. It can also depend on if you are planning to explore the countryside independently, and whether or not you're comfortable driving in Italy - and doing the homework needed - or would prefer to travel mostly via public transit.
That said, Florence would be about as centralized as you can get. It also provides reasonably easy access via public transit (train or bus) for any number of day trips in Tuscany. The city itself is marvelous IF you are interested in what she has to offer.