There is at least one situation in which you might expect something different under MWI than under pilot-wave: quantum suicide. If you rig a gun so that it kills you if a photon passes through a half-silvered mirror, then under MWI (and some possibly reasonable assumptions about consciousness) you would expect the photon to never pass through the mirror no matter how many experiments you perform, but under pilot-wave you would expect to be dead after the first few experiments.
I'm not convinced there's a real difference there.
In both cases you expect that in no experiment you observe (and survive) will the gun fire and kill you. In both cases you expect that an independent observer will see the gun fire and kill you about half the time. In both cases you expect that there is some chance that you survive through many experiments (and, I repeat, that in all those you will find that the gun didn't fire or fired in some unintended way or something) -- what actual observable difference is there here?
What is something you used to believe, preferably something concrete with direct or implied predictions, that you now know was dead wrong. Was your belief rational given what you knew and could know back then, or was it irrational, and why?
Edit: I feel like some of these are getting a bit glib and political. Please try to explain what false assumptions or biases were underlying your beliefs - be introspective - this is LW after all.