Great discussion here. In my experience, psychedelics have not "changed my preference ordering" (at least not notably) but have helped me change the narrative that I tell myself on an ongoing basis. During one mushroom trip, for example, I felt very much like a child -- overwhelmed and vulnerable at times, but also unusually engaged by my own sensory experience. That state of mind partially stuck with me after the fact. I've come to see myself as a work in progress rather than as a "formed" adult. I'm more inclined to embrace new challenges even when they might end in failure. Other experiences have also helped, including yoga and reading Eliezer's OB posts. I highly recommend the experiment (assuming a reliable source of material) and would happily send a narrative description of my experience with another drug to interested parties. (nathan (dot) labenz (at) gmail (dot) com)

(Disclosure: I have tried the whole suite of safe psychedelics, and psilocybin was valuable but probably least valuable.)