You would have to ride Star Tours 2 for six hours straight to have all 54 possible experiences.
I love Star Tours, especially since the upgrade. C-3PO is a fun addition as the "pilot." We have ridden several times and have been to Hoth, Tatooine, Coruscant, and flown through an asteroid field before seeing the unfinished Death Star. There are a few scenes we have not experienced yet, but hopefully one day, we will manage to see them all ... well, hopefully, without having to ride for 6 hours straight.