One's tour experience is absolutely dependent on the guide you end up with. Unfortunately, our guide just wasn't up to par. I had previously had positive experience of a Viator private tour in Paris in 2016, so I paid the required 380 min 4 adults though there were only 3 of us: my son, grandson and me. Our tour started about 30 minutes late because our tour guide called from another hotel parking lot asking where we were. I had to hand my phone to the doorman to help the tour guide pick us up. Basically we were taken to and dropped off for photos and a quick walk through then picked up at about 7 sites. Either the guide was not comfortable with the material or was distracted, but we didn't learn anything more that we could have read in a brochure. The Vietnam memorial was confusing because we didn't know anything about how it was organized prior to walking through. My expectation was that we would have been given information prior to being dropped off. Our guide highly recommended a food court for lunch which Im guessing worked out better for her than for us. Needless to say it was extremely disappointing so we finished earlier than the 60 minutes set aside so we had to wait about 15-20 minutes for her to pick us up. We happily ended this tour early in favor of seeing a museum where we asked to be dropped off. All in all, our 6 hour tour ended up being about 4.5 hours, minus 1 hour for lunch and 15-20 minutes at each of the 5-6 sites where we were dropped off. Hop on Hop off or even Ubers would have been equally as good and certainly a great deal more satisfying and cheaper.