I chose the intense hike, and if you like a challenging hike (lots of inclines) and little bit of scrambling up rocks, it is lots of fun!
I did my hike solo with Chad, who is an amazing guide. I was a little worried what I'd talk about with a total stranger for 4 hours, but our conversations were quite entertaining, and I learned a lot! He talked at length about the geography, botany, and history of the Valley of Fire, and as a very curious person, I loved it. I peppered him with questions, and he was totally cool with it.
The 'trail' we did, if you can call it that, went just a bit into the park. I didn't realize how little ground you can actually cover in only 2 hours with all the ups and downs (and then going back). It makes me want to return but with more time! I always felt completely comfortable following Chad's lead as we went up and down the rock sides. Not once was I afraid-- he was great at telling me where to put my feet.
The landscape is gorgeous, it's completely silent, and it clears the mind. I loved seeing the animal tracks, bighorn sheep, and cool petroglyphs.
Waking up at 5am to do this is worth it. Make sure you bring real shoes for hiking and a light jacket. They have spare backpacks to lend you. The truck had water and gatorade, but I was happy I brought bananas and a granola bar.
I highly recommend the Intense Tour for those who want to really get into the nature of the park.