I can only speak for Florence, since I've only taken the local bus there. I have to say I was so nervous about it. Normally I take the bus everywhere, but after doing some research, I decided to avoid it on my first go around to Italy. It seemed super daunting. For example, what I read said that the fare collector is usually in the middle of the bus, and if you failed to give your fare for whatever reason, you'd be fined an exorbitant amount. There were a few stories from tourists who had been fined for that reason, because they were confused about how to give their fare. The second time around in Florence, which was last year, I decided to give it a go. I went to the local station to buy my tickets in advance so as not to deal with any of that. When I got on the bus, the fare/ticket collector was in the front of the bus like in most buses. However, exiting the bus was kind of confusing because there's a middle door to exit, yet no one seemed to use it, nor did the drivers open it EVER. But the most confusing thing to me was the fact that there are at least 7 different bus companies. Usually there's one bus company per city or region. Like in southeastern PA, there's Septa, or in greater Atlanta, there's MARTA. So the fact that there were several options with different times and prices was hella confusing. So if you're going to take the bus, prepare yourself for all that.