We had done trolley tours with this same company in Savannah, GA and in Boston, MA, so we were familiar with the format. We like being able to hop on and off at our pleasure, with the narration as we travel. There was a lot of walking with the orange route to get to places we wanted to see. We'd love to see a few more stops to reduce the walking load for those of us who are seniors.
The actual Trolley tour was very good. However the problem is with Viator. When booking the tour on Viator's website, they give the appearance that the purchase is date specific. However when you exchange the voucher with the Trolley representative, they clearly state that the voucher can be used for any day. Also the information provided on Viator's website was incorrect and not up to date. We purchased a two day pass and found out when we got to DC that one of the days we planned on touring could not be used since the Trolley service was not running that day. Although we could have used the second day passes another day, we were leaving DC and could not use them. Therefore the money we spent for the second day was lost. The Trolley Tour company had posted on their website the fact that there would be no service that day. However, it was not posted on Viator's website. They indicated that the day was available. The lesson here is that the passes are not date specific as you are led to believe and you need to check with the actual tour company to make sure they are running. You might be better off just dealing with the actual tour company rather than Viator.
Very good tour with good narrators. You can see the best of Washington. I expect however that in the busy season getting on a bus can become problematic as we were out of season and had to wait for second bus at a pickup