I have the following question about travel in Italy. I plan to go borh to Rome and Florence, but I am also interested in seeing small towns, such as Orvieto, Assisi, and Siena. I plan to day-trip to those towns while staying in large cities.
Some people do just the opposite.
Take the SITA bus, it's faster and cheaper. Assisi is equidistant from Florence or Rome, but a long way to day trip. It may be worth staying the night to really enjoy your visit. This is true of most small touristy towns. They are much more enjoyable after the day trippers have left.