We will be traveling from Rome (Roma Termini) to Cortona ( Camucia), then Cortona to Monterosso, and then back to Rome over a 15 day period in June 2018. Is it advisable and possible to purchase the tickets ahead of time to insure we have seats? If so....
What web site is best?
What train is the best/ most reliable?
Is it worth it to travel first class?
Here is the deal. The fastest direct trains from Termini to Camucia-Cortona are Regionali. They are only 2nd class, they don't take reservations, it is first come first served (seated), and it is always the same price (11.55 EUR per person) whether you buy a month in advance or 1 minute before departure with a smart phone app.
Since the train originates at Rome Termini, it will be spotted on the track 10 or 15 minutes before scheduled departure, so be standing there then and you will be the first on board and can grab your preferred seats.
Going to Monterosso will also probably on all Regionali as well, but you'll be catching a train that is continuing on a route, so you'll just have to find a couple of seats. Expect to make at least a couple of train changes on the way.
Monterosso to Rome will best be on an IC train, or maybe even a Freccia train. There you can buy up to 4 months in advance for the best price with seat reservations, and sometimes an upgrade to 1st class is just a few more EUR. These tickets have to be used on the train specified on the ticket, kind of like an airline ticket.
Everyone travelling by train in Europe should look at the volumes of advice on www.seat61.com
Hi. Good advice from Sam. One thing to add is that schedules / tickets for after mid June are usually not available until April or even May, so if your Mont - Rome trip is after about June 10, wait until later to look for / buy tix. Enjoy your trip!