The exhibit itself was marvelous, once you got through the venue's terrible unorganized manner of getting to it (hardly any signs even though you had to go around and about and down stairs to even have your ticket taken). It was full of props and costumes, organized roughly by theme (quidditch, bad guys, Hogwarts great hall, etc.) My favorite things were the costumes--so intricate and attentive to detail that would never be seen on screen. No photos were allowed, and I'm glad, because I would have been distracted from looking, plus distracted by flashes going.
I felt it was well worth the $25 ticket.