When travelling between Florence and Orvieto, everyone is advised to take the unreserved regionale train and AVOID the reserved Intercity train. Here's why:
1. The unreserved regionale train originates at Firenze Santa Maria Novella (SMN) Station. By contrast, 5 of the 6 reserved Intercity trains transit through Firenze RIFREDI Station (and NOT SMN), which means that passengers must purchase a ticket between SMN and RIFREDI (1.40) and make a train connection. This extra step erases any time advantage that would be gained by taking the Intercity train (which makes fewer stops). Moreover, because the Intercity train originates in northern Italy, it could be running late.
2. The unreserved regionale train costs only 13.60 Euros, versus 19 Euros for the Intercity (plus 1.40 Euros for the connection between SMN and RIFREDI).
3. Because the unreserved regionale train originates at Firenze SMN, there's hardly EVER a problem finding a seat, provided you board promptly.
4. There is no real comfort advantage with the Intercity train. In fact, the newly restyled regionale train uses Intercity rolling stock, and seats are comfortably firm. Note however that second class seats do not recline, whereas first class seats do.
5. The regionale train operates every two hours on average, takes slightly more than two hours to reach Orvieto, and makes 11 stops.
6. There is no food or beverage service on the regionale train. All trains are non-smoking and are supposed to be air conditioned (during hot weather).
You can easily visit Orvieto as a day trip out of Florence (or Rome), although it's much preferable to spend at least one night in the wonderful south Umbrian city, since there is quite a bit to see, and an after-dinner stroll along Orvieto's narrow streets is most worthwhile.
Also, take the unreserved regionale train between Orvieto and Rome, since the extra cost of the reserved Intercity train is not money well spent.Edited: 8:30 pm, August 25, 2012