A few notes after my first visit:
Foremost, the scale of the interiors is massive. The screens and rock-work, the projected waterfall and the wall of vault doors make me wish for an evac in that scene.
The thrill factor is excellent in my opinion. Rides like FJ, HRR and even Simpsons put me on the verge of nausea. Gringott's is exciting without the sickness.
The story leaves a bit to be desired. I wonder what would have been created had Radcliffe participated. One more Voldemort appearance would have been great as well.
Arrived 6:25 am Friday, entered the land at 7. The ride had a delayed opening. Sat just outside the lobby until 8:05. One side loading.
Arrived 6:15 am Saturday, entered the land early (6:45), ride was loading both sides. Rode once standby, once single rider, done by 7:15.
Curiously, they were loading entire rows with single riders even though that line only reached the bottom of the staircase.
Overall, my favorite ride at UOR. Can't wait to experience it again.