This tour to see how 747's, 777's, 787's etc. are assembled is utterly amazing. Greg, our tour guide, was a walking encyclopedia of facts, figures, and details. There's so much information that you can't possibly retain all of the interesting and fascinating tidbits.
I have friends who live in the area who have never done this tour. I've now told them they really should do it. I visit frequently from Canada and the Boeing tour has been on my list of 'Things to Do'. I'm only sorry it took me six years to do it. It is definitely worth a repeat visit.