The Trolley tour allows you to see a lot of San Diego in a single day without having to worry about directions, driving, parking, etc. The narration by the bus drivers was just OK-- not terribly entertaining. At times it felt like they must be getting paid to plug businesses in the area. The seats on the bus were less than comfortable for a person with long legs (I'm 6'3"). The hop-on, hop-off feature allows you to get off to explore neighborhoods on foot. There were 12 stops, I think. But then, if the next bus was too full, you'd have to spend a lot of time waiting for the next bus-- and that one might be full, too! It was OK. I'm not warning you against it, but I'm not really recommending it, either.