We booked shuttle from Tampa cruise port to the airport. The local company that was connected with Viator was SuperShuttle. SuperShuttle would not honor our paid vouchure that we had in hand. They claimed that we were not on their list. They offered to take us for additional payment in cash. We called Viator, they verified we had paid for their services, they spoke to the SuperShuttle rep on site, and as we ended our conversation the Viator rep said, "Good luck." Well, not "good luck" didn't come our way. We were told the next shuttle was just about there and that they would take us to the airport. There was quite a delay and then we were told that that shuttle wasn't going to the airport. This happened more than once. We ended up having to pay another service to transport us to the airport. Save your money, save the headaches, don't use Viator!!!

I reserved a private transport from newark to manhattan I waited for 20 minutes ,called 3 times. I paid 48 euros (55 american dollars viator) and the driver asked for 26 dollars more for the peage when we arrived at the hotel! And tip Too expensive Really

We found this service on Paris Insiders Guide. This website is powere by viator and the company they've partnered up with is Paris Shuttle. We pre-paid for this service. We phoned them a total of 4 times at the airport in an hour because they kept telling us to wait. The driver arrived after our 4th call, he had no sign with our names on it, took another hour to pick others up. Even though we were first on, we were last off and the whole ordeal took 4 hours. I got duped by their viator website: Paris Insiders Guide. Terrible service, rocky start to our honeymoon. 4 hours when it should have been less than 1!

Do not ever use VIATOR Tour shuttle service in Rome. You pay in advance but they do not show up at the airport.
We waited for 1,5 hrs in the hope they would finally pick us up. We asked all travel services at the airport if they knew them, no one did. They were not reachable by phone or in person.
Back in Holland we tried to get our money back but they told us we had to come to their office in Rome.

Booked car transfer from Airport to Lisbon city Hotel Portugal. The transfer was 5 minutes late but we stood next to our name taped to the rail until someone arrived. The drive to the hotel was 15 minutes. The driver never spoke and read the paper at the stop lights! Had booked for return transfer to the airport and no one came for us!! Frantically tried to ring the local number and the emergency number with no answer. Hotel receptionist tried also with no luck. Called a taxi and made it with 5 minutes to boarding closed.

So unprofessional!!! NEVER EVER AGAIN - NEVER EVER EVER AGAIN!!!! Get a taxi they are everywhere and works out cheaper!!!!!! Don't want to give any stars / rating for some of these categories (Unfortunately the site wont allow it!!)