I had a full day tour with David this past summer. His English was exceptional. He was easy to connect with and very patient. This was not the typical dry, scholastic tour but a real introduction to everything that is Italian and Pisan in particular. He was exeptional in conveying historical and cultural info of all kinds. We had a great time and lots of laughs as well. Since most people will only spend a day or so in Pisa spending at least part of the day with "Pisa Explorer" is a wise choice for those who wish to maximize their travel experience.