We just got back from a WDW trip and used the CARES harness for our 2.5 yo. We rented it from e-bay and had minimal problems with it. He stayed in it and did not try to escape (he was also busy watching finding Nemo the whole time). The only problem we ran into was that his butt kept slidding down the seat since there is no belt to go between the legs. If you use this device I would recommend getting a small rubber mat to put on the seat so that they do not slide.