I've taken a tour with City Sightseeing in Toronto twice (the recent time this past weekend), and they give decent tours in my view. How much you enjoy the tour really depends on your tour guide and the bus you take. Thankfully, the tours I have taken with them have had excellent, charming tour guides ( even if their jokes and puns can get annoying). The buses are not in the best condition; I highly suggest riding on top of their double deckers if possible. If you do hop off at any stop, expect about a 20 minute wait for the next bus. Overall, they give adequate tours, but they are not the best.