It's pretty nice to have the free Toy Story bus available as an option, especially at the end of a long day in the parks. They run constantly. The only waiting you will do is to board depending on how busy they are as they cycle the buses through. Also be aware that the walk back to either hotel from the park isn't exactly a scenic stroll. It's just busy city streets with lots of hotels, small shopping centers etc. Maybe try following the route to each hotel down Harbor/Katella on Google Street View to give you an idea?