This is a good place to go hike if you just want to wander around, take in the scenery, and think. I stopped many time to admire the hill country views or inspect plants, rocks, and fossils (there was one portion of the Indian Grass Trail where the ground is just covered with marine fossils, a reminder that this area once was a shallow sea).
I managed to walk all of the marked trails, though this involved doubling back on some portions. The total trail mileage is less than 6, but you can make it a longer hike by doing what I did. Also, walking both directions on certain parts of the trail gives you different views. My favorite views were had from the Indian Grass Trail.
The parking lot was pretty full but I did not encounter as many people as I thought I would on the trail. There were a couple of families I passed, but other than that it was pretty quiet aside from the highway sounds.
The terrain was easy for me. The most difficult part was ascending/descending Rimrock Trail from/to the main trail head, but that wasn't bad at all. If you hike a lot you should be fine.
Be sure to bring you own water; there is not a place to fill up here.