Washington D.C., District of Columbia
I and my family were REALLY disappointed in this tour.
First of all, we arrived at Union Station and went to the front of the Postal Museum to meet the tour as instructed. When I saw no sign for the tour, I called the number that was the designated "local contact" on my email confirmation. They were supremely unhelpgul and furthermore said they had no knowledge of Viator - which then made me panic that I had been swindled.
By luck we then saw an open top tour bus directly in front of Union Station. We made our way and asked the offical reps who were there if we were in the right place. Thankfully they acknowledged our receipt and we got our tickets issued.
The tour itself took us to the promised places. But what was really disappointing was the recorded commentary. The people in charge of it did a very poor job of keeping the commentary up to date with what we were seeing. Most of the times the commentary started up again, it started in the wrong place, referring to sights we already saw. It was then hastily stopped in mid-sentence and started back up again, most times again in the wrong place. By the time the commentary got to the correct place, most times we had already passed by the historical site. It was a very frustrating experience. In this digital age I cannot imagine that syncing the commentary with what we are seeing outside, or starting it up at particular points, can be so difficult.
The driver was also quite aggressive - almost knocking a small tree over in Georgetown. The low branches that you face on the top of the bus on the route are quite dangerous also.
A disappointing experience overall.