Was there in late Dec. stayed in both campgrounds. Dusting of snow in places and sub freezing nights. Arch Rock never filled-as said it is the tighter, no hookup, and less big rig friendly of the campgrounds. But IMO it is the most scenic where I had my own rock "cove." My friend got his 35' bus in one of the sites and had his own cove. Didn't get much solar generation from low angle sun and the rock's shade. Atlatl has power and water as I recall. Arrive early for best chance and choice of first come first served sites. Dump station near campgrounds. We had a good stay and enjoyed it.
I was able to get useful (if cranky) VZ data in both campgrounds with the weboost (clear cut example of the booster being useful). Without it nothing or occasional 1X text. Some of the hiking areas had better service. ATT no better.