I have stayed at this campground 2 times over the past few years. The last time was for a  fun 1 night weekend visit to watch meteor showers with a group. The skies were awesome! 

The bathroom wasn't amazing but was usable. The campground while on the edge of joshua tree is not really inside the park. You don't pay park fees, but you can't go directly into the rest of the part from the campsite. 

The plus here is that you can get reservations fairly easily. The campsite was pretty busy for both trips. The hills around the campsite are fun to hike around on, but don't compare to the rest of the park. 

We also came here in January a few years ago and it was very cold and windy. We even got rain while we were there. Just remember to tie down your tent well!