I contacted the driver before we left San Francisco to inform him that due to a flight delay we would be arriving at a new time on a different airline. When we arrived in Frankfurt I once again contacted the driver to confirm our arrival time and location. There was no one there to meet us. TERRIBLE!
I am averaging two transfers that I arranged. The first is 5 stars. We were met as soon as we arrived and taken promptly via a luxury van to our hotel in downtown Madrid by a very nice man. This was exactly what I was expecting since I knew we were arriving in a country we had never been to before and did not speak the language. The other transfer was for our travel companions who were arriving about one hour after us and I would give zero or one star for their experience. Apparently, on most Saturday mornings there are races in downtown Madrid that require street closings. As the race progresses the streets reopen. My companions were impacted by the race. The driver got as far as he said he could go and dropped them off about a mile from the hotel to return to the airport for another transfer. They didn't know where they were and were left to fend for themselves after a transatlantic overnight trip. Thankfully, they made it and a police officer ended up walking them the final portion to the hotel to ensure they made it OK. They are elderly and this was, in my opinion, disastrous. My advice is if you want to book this, check with Viator to ensure the route, destination and timing won't produce a similar result.
Driver was very courteous and helpful and car MB E car was in new condition and very comfortable. Although the private car was 2 or more times a taxi, it was worth it for getting out of the airport to the hotel with luggage after an overnight flight of 7 plus hours.