On any review site, I always take into account the number of reviews. People tend to complain more often than praise, so a low number of complainers isn't necessarily indicative of a bad review. And certainly, a park with 2 reviews (1 good and 1 bad) is not a review at all. The good is the park owner, the bad is his/her nearest competitor.
We used RVParkReviews on our 6 month trip and found the reviews of the places we stayed were pretty accurate, except one spot. Of course, the places we didn't go because it got panned on the site we know nothing about.