FCO to Sorrento

We used our Sorrento hotel's land services partner for two black car rides, 8 hours on the Amalfi Coast, and transfer back from the hotel to the Naples rail station. We figured they had a strong incentive to provide good service to hotel guests. And it turned out we could charge the bill to our room account.

Since the most common vehicle is a Mercedes sedan, four people and their luggage are a very tight fit. You may need to pay extra for a larger vehicle. Naturally, side trips add substantial cost, as does a one-way ride for a very long distance, with an empty return. While your characterization of the public transportation route is not far off, it's important to recognize that the Frecciarossa train service from Rome to Naples is much faster than any car or conventional-train trip. You may be giving one-seat convenience too much weight over unknown road congestion possibilities, as well as total time in the "luxury car." This is not an Uber trip across town after a bar night out!

https://goo.gl/maps/Vqm9FtCQm98ativv8

Why not describe your potential side trips? Do you mean Pompeii? That's easy to do from Sorrento on .... public transportation. But it's much hotter and sunnier in the afternoon. Pompeii does have a luncheonette inside, but in general, food options there are limited. Do you dream of Vesuvius as well? What does "be open to" mean? It's not advisable to try to change a black car booking with multiple additional hours after you have boarded the car.

I trust you have made plans to (itinerary not given) get back to Rome the night before any FCO flight home to the U.S.

Since most romans use the cheaper FL1 train, Nobody has ever been forced to stand on the 1st class Leonardo Express from FCO to Rome. It simply doesn't happen.

The level transfer to the high speed train at Roma Termini station will take less than 10 minutes. Assuming you're using wheeled suitcases and not the old travel trunk you found in the attic, of course.

Book a driver for the last leg, from Napoli Centrale station to Sorrento. This way you will save lots of time and some money. Note that Some drivers would rather pick you up in Napoli Afragola station than driving into downtown Naples.

Incidentally, Italotreno's walk-up fare from Roma Termini to Naples is usually cheaper than Frecciarossa's, whereas the 2 trains run at the same speed.

We used the below car service 3 different times. They drove a Mercedes Van and it was perfect for 4 people plus luggage.

The owner is great!

https://www.topexcursionsorrento.com/

To add to the helpful info above....
https://www.sorrentoinsider.com/en/transfers-arrivals/rome

Between road time and cost, ouch. It's possible you could find a service for less that the estimate provided but we're hearing that private drivers have become quite expensive due to higher fuel costs. It also doesn't solve the issue of the time cooped up in a vehicle this trip could involve.

I'd more seriously consider a 'fast' Frecciarossa train to Naples, and a driver from there. It's not uncommon to add a stop at Pompeii along the way but as Tim noted, you'd need to arrange that in advance so the driver can figure in wait time. It's very easy (and cheap!) to do that one by commuter train from Sorrento so you may choose a morning for that one if you have the time on the coast for it to work?

Mondo Guides offers shared transfers now

https://www.sharedtrips.com

But honestly since you arrive the day before-what time? why not just stay near Termini- take a cab from airport- 50 euros. Stay the night. Walk to Termini and take fast train to Naples in the am. You shouldn't still be so jet lagged that is is too daunting.

If you don't want deal with the Circumvesuviana then book a driver from Napoli Centrale to your hotel in Sorrento- that will cost something like 120 euro- much much less than a driver all the way from Rome.

www.topexcursionsorrento.com

We're flying to Rome in two weeks, staying the night in a hotel near Termini station, taking Italo to Naples where Moneitti Taxi is picking us up. Since our time in the area is short, we're stopping at Herculaneum on the way to Sorrento.
https://www.monettitaxi17.com/English.htm

To add to Bet's report, a car stop is especially appropriate for Herculaneum because:
1)Unlike Pompeii, Herc is a 12-15 minute downhill walk from the Circumvesuviana station.
2)Herculaneum takes less time than most visits to Pompeii

Another aspect of Herculaneum is that there is no food inside the site, and there are only a few restaurants on the main drag in modern Herc. They're good, but they only have "slow food."

I might have added, before that we were happy to pay (2014 price ... ) 90 Euros to transfer from our Sorrento hotel to the Naples rail station because the Cirvumvesuviana had been so crowded, and because we had paid a 15 Euro taxi fare for a very short drive to the hotel, in Sorrento. I think that black car fare is now 110 or 120 Euros.

I don't normally recommend that people combine London with The Continent. But because we had specifically targeted the Chelsea Flower Show before our first time in Sorrento, we had taken a bargain airline from London to Naples. Even there, we were too late to really transfer to Sorrento, so we spent the arrival night in Naples. Then we had a nice long walk (pulling our suitcases) to the Naples rail station, after seeing the Archaeology Museum with our bags at the hotel, in the morning. (Not saying this works for 4 people.)

We just researched this for our spring trip.
Expect about 500 euros for Rome to Sorrento, but since you have four adults, it's not too outrageous for the convenience. The car service needs to get the car back to the point of origin.
Naples to Sorrento is about 100 euros.
Most of the services want cash.
We actually found one recommended service that will take USD, and when we figured out the conversion rates, it was quite fair, and saves the service fees from the atm machines. ( Our bank has no foreign transaction fee, but the banks in Italy do, we have found.)
We actually have a package deal, using the same service for our day trip along the coastline, which saved a little.
Safe travels!