Well....

They sometimes read way into certain jokes and stuff, but on the whole, they are a great reference.
Some people have been complaining that the Family Friendliness ratings are inconsistent. Well, I half agree and I half don't.
You have to understand that they rate based on the typical age of the targeted audience of the film. So while the Hunger Games might get a 3 star rating (since it is directed towards teens and adults), "We Bought a Zoo" might get the same rating (since it is directed towards people around the age of 8+) even though the Hunger Games is way more violent.
Pretty good, just a little bit... Religious, for want of a better word.
Hope this helped!!