I'm also eager to read people's reports, not just for the double-booking thing, but for impressions and pictures of viewing areas, and whether people could move their pre-booked fast passes around on the day of using
MDE. (I'd be a bit annoyed to have to call DSS to move those if you're in the park, unexpected things happen, and you want to check for a better fp time. I vaguely remember reading that you should be able to adjust these yourself on the day of, but I can't find the reference and may be mistaken.)