Staying at Petr's house was really nice. He suggested to pick us up at the airport because we were arriving late. He really made us feel welcome by showing us the neighborhood, like where to take the bus, the store, the restaurant, the university where we had a three days course. He even got some basic food for us, so we could have easy breakfast in the morning. Also the center of Prague is easy accessible from his house by bus and metro. Really nice place!