It’s at the Woodfield Mall, which is only about 5 minutes away from where they do BrickWorld Chicago. (The mall has a Lego store and it’s also only about 20 minutes from Rachel’s house, so I was already familiar with it before the museum opened.)
Adam Reed Tucker did a ‘soft opening’ when we were there, basically it meant that they were still working on installing stuff, but he wanted to those of us attending BrickWorld to be able to come see it while we were in town. We were impressed with what we saw (and Rachel has 20 years as a museum exhibit designer, so if she hadn’t been impressed, I would’ve heard all about it). I think the official grand opening has occurred since we were there.
I’m pretty sure there’s a BTB video about it, they happened to be there filming the inside of The Vault while we were there (we weren’t allowed in).
I don’t know if it alone justifies a trip out there, but of course once you’re there it’s not like you’ll have a hard time finding other stuff to do in Chicago. Of course, you could also just wait and go to BrickWorld as an attendee next year. BrickWorld is awesome.