In contrast to every other Hop-on Hop-off bus I have ever taken, this bus service did not have a prerecorded commentary available in different languages. Instead, there was a live commentator on the bus. The problem was that on one bus we took, the commentary was 100% in German and on the other bus it was 90% in German, even though the commentator checked with us to see if we were English-speaking. What commentary we did understand seemed geared to being funny rather than informative. Bottom line: unless you speak German, this bus service cannot be recommended.

Very knowledgeable and organized guide. We got through security and ticketing quite quickly and we're given a good overview of the museums, though it was disappointing that we had to skip the art gallery completely. (In fairness, unless you had a week to devote to the museums, you can only see a selection of the items.)

The guide was very good, though all the commentary was done in English, then French and then Spanish, so that the commentary was virtually non-stop on the bus. In Siena, we had a separate English-speaking group with an excellent guide who really helped bring the city alive. (She was herself a resident.) There was no guided tour of San Gimignano; we were just given an hour to wander around on our own.

This is a pretty good way to get around to the highlights of the city. The only limitation is that the bus does not go through the very heart of the city (cathedral and palzzo vecchio area), I imagine because of the crowded and narrow streets. However, those are areas that you want to walk on your own anyway.