NO, I'm not kidding .... read on:
As many saavy travellers already know, there are three categories of Trenitalia trains in service between Rome and Florence:
1) Super-fast Frecciarossa/Frecciargento (reserved seats), which take 92 minutes along the high-speed rail line and operate every 15-30 minutes through the day. Effective June 9, many of these trains will stop at BOTH Roma Termini AND Roma Tiburtina stations.
2) Intercity (reserved seats), which take three hours along the traditional rail line, make a couple of stops en-route, and utilize Firenze RIFREDI station instead of the more centrally located Firenze SMN.
3) Regionale Veloce (UNRESERVED seats), which take up to nearly four hours along the traditional rail line, make a multitude of stops en-route, and terminate/originate at Firenze SMN. These slow trains run roughly every two hours.
Now, it can be said that the large majority of foreigners prefer to take the fast Freccia train, especially when a discounted ECONOMY or SUPER ECONOMY fare can be had by purchasing in advance (the lowest fare is currently 19 Euros on this trip).
However, Trenitalia recently tightened the rules for its discounted tickets on the reserved trains, which fares are no longer offered for sale on the travel date itself (the purchase deadline is 23:59 (Italy time) of the day PRIOR to scheduled travel). That means, for example, that travellers no longer have the option of seeking a slightly reduced fare even a few minutes prior to scheduled train departure (this option was especially valuable for those taking the train immediately after arrival by plane, who were hesitant to book in advance owing to the risk of missing the train and forfeiting the discounted ticket).
Now that these discounted tickets are no longer available at the last moment (the sole exception being the "Familia" fare), the cost of the Freccia train is the full "BASE" fare (currently 43 Euros), which is somewhat expensive, especially when there are multiple travellers (children up to the age of 15 years, 0 days still qualify for the 50% child's rate, and toddlers up to the age of 4 years, 0 days still can travel for free (on ANY train), without a ticket and without a guaranteed seat).
SO, some travellers may be looking for a cheaper alternative, which leads us to the unreserved regionale veloce train. While the trip is long (up to four hours), and makes many stops, the railcars are modern (refurbished Intercity cars are used), and the new seat layout is practical and appealing. The fare is also very appealing: the "ordinaria" fare is currently 20.25 Euros, with no discounts for an advance purchase. Children between the ages of 4 years, 1 day and 12 years, 0 days get the 50% child's discount. Traditional PAPER tickets can be purchased up to TWO MONTHS in advance, and the ticket has a validity of SIX HOURS once it is "validated" in the stamping machine by the train track. Tickets can be purchased from most electronic machines, or by standing in line at the manned ticket agent windows. The train also stops at Roma Tiburtina and Firenze Campo di Marte stations, for those who care. The regionale veloce costs less than half of the Freccia (and takes more than twice as long), so it's a good choice for those wanting to save money.
HINT: While the seats on the regionale veloce are acceptably comfortable, they do NOT recline. By contrast, the FIRST CLASS seats (currently 31 Euros) do recline, and are a bit wider, consequently more comfortable. Each person will decide whether the 53% surcharge is worthwhile.
UNRESERVED SEATS: Don't fret, because the regionale veloce originates and terminates both at Roma Termini and Firenze SMN, you are guaranteed a seat if you board early.
NO FOOD OR BEVERAGE SOLD on the regionale veloce, so bring some with you!
LUGGAGE STORAGE: Plenty or room available in the overhead racks. Luggage too heavy to be lifted will need to be placed on the floor, preferably next a solo seat in the railcar, but not blocking the aisle.
HEATING/AIR CONDITIONING: present on the regionale veloce, except when malfunctioning!
LOTS OF STOPS: You'll get to see the Italian hinterland adjacent to these smallish intermediate stations, and the train speed won't limit enjoyment of the scenery (as it can on the Freccia train).
DON'T FORGET TO VALIDATE PAPER TICKET, or you will risk a big fine. By contrast, electronic tickets (regionale OR reserved trains), as well as paper tickets for the reserved trains do NOT need to be validated.
CAN BREAK JOURNEY: ONLY on the regionale trains (and NOT on the reserved trains), you are allowed to break your trip with one (or even more) short stopovers (e.g. in Orvieto or Arezzo), without needing to purchase a new ticket for the second leg, AS LONG AS you re-board your final train DURING the six-hour VALIDITY of the PAPER ticket, and don't abuse the privilege such that you MIGHT be questioned (e.g. by boarding within 5-15 minutes of its validity, when the balance of the trip takes over two hours).
Here is the official rule:
"In particolare, il viaggio deve essere terminato entro 6 ore dal momento della convalida. Il viaggiatore che si trova in treno allo scadere della validità del biglietto può proseguire il viaggio già iniziato fino alla stazione di destinazione senza effettuare fermate intermedie se non per cambio con il primo treno utile." OFFICIAL TRENITALIA RULES PART III (Trasporto Regionale) Section 16 Paragraph 3
As as alternative, what about taking the reserved Intercity train ("BASE" fare currently 33.50 Euros)? BAD DEAL, in my opinion (except at the SUPER ECONOMY fare of 9 Euros), because travel time (three hours) plus the need to CONNECT to a regionale train at Firenze Rifredi, result in a total transit time nearly equal to that of the cheaper and more convenient regionale veloce! Moreover, some Intercity railcars can be very old and needing of an upgrade.
So, the tradeoff is straightforward: in the absence of a discounted advance-purchase fare on the faster trains, you currently pay either 43 Euros for the fast Freccia, or 20.25 Euros for the much slower but not uncomfortable regionale veloce.
Something to consider before forking out twice as much money!!!
NOTE: you will find some people who can't be persuaded to ever take the regionale veloce train on this route, and others who have taken it multiple times and continue doing so.
HINT: You can also check for discounted fares on competitor ITALO TRENO (which departs from Roma TIBURTINA station), which can sometimes be very attractive. However, it's quite unlikely that you'll find any discounted fares at the last moment (same day travel).
BEWARE: The discounted fares on the reserved trains are nonrefundable (except the "Familia" fare) and some are non-changeable as well. Caveat emptor!