We picked up the tour at its start on a Sunday in August, 2013. I had no expectation of a very informative tour, but it seemed like a good way to see the city in 2.5 hours. The tour guide, while he did stress safety issues and did offer advice when asked questions, started out the first run of the morning by complaining that he had a day full of this blather to spew (paraphrase). He was fairly unengaged during his delivery throughout, and I think a pre-recorded tour would have been much better in this case. It was bad enough that he so obviously was just putting in his time, but he seemed to expect that the tourists were on his side - as if, having just plunked down $25 for a tour, we realized how silly the whole thing was.
The seat belts on the upper deck did not work in all of the seats that I tried, and my 3 family members had the same experience. If that bus were to topple in an accident, it would be bad news. The guide's response was that we shouldn't worry, since the bus would not go above 5 mph (which was not true, of course).
This tour didn't work well as a hop on/off tour, since the gap between the bus runs was over an hour. We got off at one stop, and we needed to wait a long time to rejoin the tour. Even so, when the bus did come, it was earlier than we had expected, I think by as much as 10 minutes. Considering that it was the last run of the day, I feel sorry for any people who may have been stranded as a result.
The script didn't contain much information, much less than on any tour I've taken, but it's possible that the guide just didn't care to deliver it.