We were intent on hiking, but it was July, and that just wasn't going to happen. We got some good info at the visitor center and set off.
It turns out you don't need to do any serious hiking to enjoy Red Rock. It's absolutely worthwhile to drive the circuit and wander off on short walks from any of the stops along the way. Or just sit and enjoy the quiet.
The vistas were so spectacular (even on the drive from Vegas!) that I burst into laughter at how amazing it all was. I'd say this is a must-see for any Vegas trip over a day or two.