I came on the recommendation of a friend and was not disappointed. The entire museum was engaging, and managed to be thought-provoking while feeling like a playground.
James Turrell's Pleiades permenant exhibition is not to be missed. It takes patience, and I personally think it is best observed in silence.
The day I went, it was snowy, and a tramp through the garden was cut a little short. It was much more cozy to stop in at the temporary art house, The Tom Museum, and catch a round of art/miniature golf.
The kids area activities were fun (although there were no kids in our party), and it was a great opportunity to chat with the knowledgeable staff.
Contemporary art often doesn't appeal to everyone, but for a fan of newer work by living artists, this is a great museum.