Bus/Train Rule of Thumb

No big rule of thumb here. Either SENA bus or train is just fine. A couple of things, however. First, the bus leaves from a station across the street from the Rome Tiburtuna train station. Thus, you have to understand how to get to that train station. It's easy to do on the Metro B line to Ribibbia. The great thing about the bus is that it stops in Siena at the city wall. The train runs from the Rome Termini to Siena via Chiusi where you will change trains. The trains will all be either IC or Regionale trains. These are slower trains. If you want, you can take the high-speed to Florence and then take the Regionale to Siena. Same journey time but more money. One downside of the train station is that it is about a mile from the Siena City wall and slightly downhill. You can walk it, take a taxi or a local bus to the entrances to the City. For your journey to Florence, you have the same choices. For the bus, take the SITA Corse Rapide (Express) from Siena to the SITA bus station which is about 800' from the main Florence train station. You can take the train as well.

As Larry mentions, the reason you see advice to take the bus to Siena is because the bus station is near the city center. The train station is below the city and requires taking a city bus to get in. This is a somewhat unique situation. For travel between most Italian cities, taking the train is the easiest way to travel.

Thanks. Knowing that Siena is unique, and that trains are generally a good route to go is helpful. I've got to go back over reservations, and see what hostels/hotels/B&Bs suggest in the Directions section. I appreciate the input from both of you.

Siena's "bus station" is actually in two places. From Florence and some others, it will be in the city center. Milan, Rome and many of the hill towns, will actually depart/arrive at the train station itself (easily enough to reach by city bus-luggage is fine-or a cab) We chose the bus route from Siena due to the fact that the rail options from Siena will often require transfers and that a bus is faster in that case. But, yes, Siena is often an outlier in those cases. Others being the hill towns without train service.

Would someone be kind enough to remind me whether I can use a credit card to purchase train or bus tickets, rather than needing cash? I know I can look this up....

You can use credit cards to purchase tickets. In the train stations there are self serve kiosks that take credit cards. easy to use, just touch the British flag to start so you can navigate in English