I don't think iPads are big at all.
My iPad pops into my handbag nicely. My camera, on the other hand, needs to go into a camera case and so if I brought that to the park, I'd end up carrying a handbag plus a camera bag.
It was great having my iPad at the parks in September. We could facetime the kids back home without having to be back at our hotel by 3/4PM, we could pull up our adrs without having to make a separate note of the confirmation numbers, we could check menus online and yes, we could take photos.
I have a fancy camera for work but for holiday snaps that I'm just going to post on fb or keep on the iPad, the iPad quality is fine.
I do agree that people shouldn't block other people's views of parades and such (we don't bother with parades these days) - that reminds me of back when people used to haul out their massive camcorders to block everyone's view- incredibly annoying!