4-stars if you are very interested in the subject, a museum nerd, or, got a deal (half off) on the tickets. Otherwise for the rest of the public that does not have a keen interest, or is paying full price, it's a 3-star exhibit. Like most museums, what you get out of it depends on how methodically you go through it. Your average person will not read and participate in every exhibit and for those I give this 3-stars but if you take your time (allow at least an hour and a half to go through) you can easily get 4-stars out of it. I typically go into length in my reviews but I feel that's all I really need to say about this one (see my fellow reviewers' reviews.) 3.5 stars.