My dd's (7 and 8) have done it three times, ds (5) has done it twice! They like it so much that they are scheduled to go again in July.
DH was reluctant about having ds go (he was 4 at the time) but he just loves the Mad Hatter. After he saw how much fun he had (and that there were other boys there) even DH makes sure the kids are booked at the Wonderland Tea Party when I make our ADRs.