Montecatini is exactly inthe middle between Florence and Lucca. You need 40 mins by train from the main station to reach Florence and the same time for reach Lucca. There are lots of train during the day but expecially early in the morning they are full of students that go to school in Pistoia or Pescia. Anyway train is very quick way to reach Lucca and Florence and then you don't have to "fight" with the traffic or with the parking. Also the bus is very good..it's a little more expensive, but you don't know if you can find traffic on the highway.
The cost for Motencatini-Florence Santa Maria Novella is 3.10 Euro
Remember to mark the ticket at the train station (you can see the yellow machines close to the tracks) or you'll have to pay much more on the train
Trains are the most useful transportation for Montecatini. If you wanna go to Pisa or Florence by train it takes about 1 and half hour. You can buy your tickets from offices or the machines at stations. Tickets are valid for Toscana region. To Firenze or Pisa it's the best to buy regional (50km) ticket. It costs 3.30 Euro (one way trip).
If you want to come back to Montecatini again, better to buy one more ticket to not wait in a queue when you're at Firenze or Pisa station. Also check the timetable from Trenitalia's website.
Trains are comfortable but not clean at all (depends on your train). Need to get some fresh air, open some of windows when you get in.
If you are staying in Montecatini and you want to go Firenze, you have to take the train. Trains are good enough. Seats were comfortable but there was no fresh air while we were going to Firenze early in the morning.
It takes 1 hour and 20 minutes from Montecatini Centro to Firenze Stazione. The last stop is only 20 minutes away from Duomo or Piazza Della Signoria.
There are many lines to many different locations in this Central Station. But only two of them stop at Montecatini Centro. One of them is Viareggio, the other one is Lucca.