The sub tour was great. We also did the coal mine tour. While it was okay, I think it would have been better with less people on the tour. I think we had at least 20 on our tour. Nothing like being pushed so tightly together no one can move or see what is being highlighted. It also seemed to be geared more toward kids in the information presented. If you go as a group of adults like we did, be prepared for screaming and pushy children. A lot of the interactive parts of the displays did not work for either of us. It was also very loud inside from crowd noise and several exhibits that blew loud horns etc. I am glad we saw it once but would not make a return trip unless it was for an extra special traveling exhibit.