I didn't even use the bus much. When I took it to go from Museé D'orsay to the Notre Dame It took 2 hours to go from one place to the other. I think there is no point in using this kind of buses to visit the city.
London, United Kingdom
The bus tour is not really recommended if you already have your plans around the city. It takes a really long time to go around all the stops and I had to wait a lot on the but stops. It's better just take the tube and go wherever you want.