This review is for the campers, since very little information seems to be posted about that so far.
Camping is $5 per person per night. They have cold running water and flush toilets in the bathrooms, but no shower facilities. They provide soap, paper towels and toilet paper. There's an outdoor spigot which could be used for filling water bottles. (Update: If you're heading to Enchanted Rock, I strongly recommend filling at least some water here before you go, because the water supply at E-rock is currently a little unreliable due to drought.)
The campsites are all clustered around three small loops of unpaved road, so no hiking is required, and every few campsites share a fire pit. There are picnic tables near the main building, but not at each camp site.
On the plus side, it's very near Enchanted Rock (about 6 miles). On a clear night, you get good views of the night sky. If you like music at night, from about 11 PM to maybe 1 or 2 AM, then camp closer to the main building. If not, best camp further away on the second or third loop, where the music is not as noticeable.
On the down side, the camping areas are rather rocky, and on the weekend that I was there, quite dusty. I.e. dust was blowing up under the rainfly of the tent, through the mesh panels, and onto me and everything in the tent.
I would recommend this place for people who don't get a reservation for a water site at E-rock, but don't want to hike out to the primitive sites there. In terms of difficulty of camping, it's somewhere between the two options at E-rock, but it does have the added benefit of having a store on site where you can buy things like bottled water, beer or ingredients for s'mores.
If showers or flatter campsites are important to you, then I would recommend Lady Bird Johnson park in Frederickburg. It's about 10 miles further away, but has hot showers, and is much more convenient if you intend to eat dinner or do anything in town. That could also be a cheaper option since they charge $10 per tent per night, rather than per person, which is advantageous if you have three or more people sharing one large tent. read more