It's certainly massive, and the new location at Pier 15 is a lot more accessible then it was when you had to schlep out to the Palace of Fine Arts. I was happy to see a lot more natural science stuff, especially the Bay Observatory, because the regular techie stuff never much appealed to me. Hubby was especially enamored with the parabolic mirror.
But you know, it's still basically for kids and of full of kids and more or less best suited to nerdy, tech-minded kids. So it was OK, but nothing I would do again if not forced.
So at this point, the world is now divided into two kinds of travelers coming to San Francisco. Are you an Exploratorium person or an Armory person?
I know which one I am.