I like the concept and have used it in other cities. Decided to go for the 48 hour ticket in Panama City. It's a bit difficult to understand their time schedule. Stops are too far away. There should really be a bus stop at the Biomuseo on the way back to the city as well. I wanted to take a walk from Parque de Juegos Amador towards the Biomuseo. But had to catch the bus going out to the islands again before returning to the city. The buses also drive quite fast, so it's difficult to take decent pictures.
Great way to see the city without being over tired from the walking. Takes you to great attractions so the price is well worth it.