I never really cared for part 4. The partying kids are just such empty clichés - of course the other movies had plenty of clichéd characters too, but they managed to infuse plenty of individual personality into them. Not really the case with part 4. And that whole thing with Corey Feldman turned me off too. I don't like little kids in my horror movies.
It wasn't really "bad", but it's about in the middle of the series when it comes to my favorites.