I love, love, love this place, but this is the sort of thing that inerests the crap out of me. Making our reservation online was easy-peasy. They did offer military discount.
We had a very small daytime tour which was nice since I didn't have to feel like our kids were distracting others.
Our tour guide Ashley was amazing. SO informative and some great stories behind so many (probably all) of these signs.
Perhaps I shouldn't even leave a review since I'm so biased toward this place... I would volunteer here if we lived close.
Go.... just go, night or day. A huge "don't miss" for a Vegas visit.