I booked the transfer to and from the airport so I will review them both here. The driver that met me at the airport arrived an hour after my plane arrived and made me stand around while we wait on another flight which the board showed as cancelled the whole time. The driver proceeded to drop me at the wrong hotel. He had me fill out a form with the pick up details for the transfer back to the airport. I had already arranged this with the agency, so this request seemed odd (actually it was a scam). On the return a different driver picked me up. He asked me for payment, when I said I had payed he called his office to confirm. They said I had not paid. I showed the driver my Viator voucher, which he did not honor. Said it was my problem to work out with the company, so I had to pay (again) for the transfer. Which I did. Two strikes for Viator for me, this is the second bad experience I’ve had with their service providers in Europe. Enough for me.