We bought the three day premium ticket that included a tour of Cambridge. The buses are high and give a good view as the drivers give an excellent running commentary of points of historical interest. We used our ticket on all 3 days and so met lots of different drivers who all had extra stories to tell on the route. All were patient and thoughtful and tried to tailor their talk to whoever was on the bus (if you are British, you might need to develop a thick skin or wear a badge to say that your ancestors were Irish!). Irish Pat was particularly entertaining and Cindy remembered details about customers from the previous day, asking them if they had a good evening etc. Each driver we saw was as flexible as possible and all offered to stop anywhere on the route during the last loop of the day so that customers were as close to their destination as possible.
We went on the Cambridge Loop to visit Harvard and the Natural History Museum (included with our ticket). The splash tour (also included) was really informative and the crew were friendly and entertaining. We also visited the art gallery (included with tour) and were pleasantly surprised to find something to interest all of us.
Without the tour, we wouldn't have seen or understood a fraction of what Boston has to offer. I couldn't imagine that the staff on other tours are friendlier or more helpful. We were walking towards a bus stop with a brochure in our hands and the trolley stopped to pick us up as we had been spotted by the driver. It's like being looked after for 3 days!