I don't know if that was the guide or the museum itself, but in my opinion it wasn't worth paying £40pp to do the tour. I was expecting it to be more interesting as we've booked the tour to Vatican and we were very happy with it. But this one wasn't that interesting and the only things worth seeing were Mona Lisa and Venus de Milo. But it could have been down to our tour guide.
Even if it was twice the normal price, I would definitely recommend it!!! The guide was brilliant!!! It is worth it because she told us all the story (all the most important and interesting details) about the tower, she also told about other buildings we could see from above. The tour wasn't boring, we were given some time to take pictures etc. It was a great experience!!!