I've wanted to visit the Grand Canyon for a really really long time, and finally booked a west-rim/Hoover Dam tour with these guys early Jan of 2014.
I've traveled quite a bit and have always thought of "booking a tour" as something my mother would do. I like to explore and get lost on my own for the most part (Petra, Taj, Giza, Chichen Itza, Great Barrier etc).
The guys picked my buddy and I right on time at 6am in front of MGM and provided breakfast, lunch, snacks and water. Really interesting stuff and I'm so happy I booked their tour. The guide was knowledgeable and kind of hilarious, he was closer to our age so that settled my perception of thinking I was on a tour with moms.
Hands down one of the best 'bang for your buck' tours you can take!