The tour covered 6 hours, and was quite informative, although the guide could have used some more time giving interesting information and correspondingly less to (not so funny) jokes. The lunch was however a great disappointment. Advertised as "an excellent meal", and considering the price we payed, we had some expectations. What we got was a soup with no taste at all, the main course (a selection of four) could maybe rate as ok, and a very dry and small cakeroll as dessert. In our case, we had the advantage of being a small group (15). With a larg group (there seems to be no limit in size), I expect the tour would be much more chaotic.