This was my second spring at Black Rock. In total, there were 5 of us and we all stayed at site 12, including 2 cars, even though it's supposed to be a 3 person, 1 car site. The ranger allowed it since we were able to fit everything comfortably and didn't really have enough stuff to warrant the two sites we had originally reserved. Since it was a busy weekend and they were able to resell our second site, we also got a refund for one site.
Site 12 was nice because it was close to the bathroom and water. The bathrooms, again, were reasonably clean, but no soap or paper towels. It should be noted that we did have to essentially walk between sites 3 and 4 to reach the bathroom, which was just across the "road" from site 3. We were back-to-back with site 3. We didn't feel too horrible about it because site 3 was rather large and they were rather loud.
Noise can be a downside to Black Rock, especially in the areas where the sites are closer to together, such as sites 3 and 12. Wind can also be an issue, but that's just the nature of Joshua Tree. Be prepared with enough stakes and blankets.
Something different this year was a man appearing out of the dark to sell us wood. A little creepy and I doubt he was Park-authorized, but it just added to the experience. He was visiting campsites and offering to sell bundles for $5 or $10 depending on size. Most of it was plywood and burned quickly, but it was nice to not have to go into town to get more wood. Campers were pretty nice about paying it forward if they had leftover wood too.
Overall, I would continue staying at Black Rock because of the views, the cleanliness, the nature center, and the available water.