I think we mostly enjoyed this, just for the easier transportation. The audio guide was ok, but boring. Go to the ACTUAL website of the company for the stop locations!! Trip advisor/viator gives you a receipt with instructions and stop locations, but those were not very accurate and caused us a large increase in the amount of walking we had to do to find a few of the stops.
We chose this tour over other HOHO tours because it offered many different options based on personal preferences. For example, we bought a ticket to use without disembarking, saving a lot of money. Also, we could validate our online-bought ticket on the bus itself and didn't have to go to the tour office. The tour was good the driver and host on board were polite. We did it on a Sunday, so it took us through Popolo Square instead of Via del Tritone Spanish Steps, Trevi Fountain. We did not get off the bus but used the 90-minute round trip to orient ourselves and get a feel of Rome. We also used it to get a birds eye view of places you don't plan to visit. We did, of course, look at the route map online before our purchase, because, while all HOHOs take you to the main sites, there are some tweaks based on their target audience.