I use RV Reviews all the time. The only issue being CGs that have very few reviews or the reviews are old. Like Olympic event judging, I tend to throw out the best and worst reviews, because some people get upset about the strangest things that have no influence on my selection.
Lately I've been trying to go to state CGs that have at least electric hookups. Typically their sites are larger than private CGs. If only staying for a few nights, I can drain the tanks at the dump station on the way out. Unfortunately my home state of NJ does not offer any utilities at their CGs, so we only go when we don't need heat or A/C.