Took a Valley of Fire tour. Guide was great, scenery - OK. Buggy was beaten up, steering had problems, was locking up - not very safe; also was underpowered - not much fun. Took longer than quoted round-trip time (~9+ hours from hotel and back). Place looks kinda crappy - was really surprised by the way equipment, office looks - very non Vegas-like.
At the end - your typical "make-as-much-money-from-vegas-tourists-as-you-can-without-spending-anything-on-good-service" stuff.