The high rating is not meant to reflect the the role playing system itself (though I think it is a fun system) but just as a mark of the pure enjoyment it is to read this book. I have yet to come across any RPG rulebook that builds as much excitement for its games as this one.
I'm totally a game snob and 3.5 is my favorite version of D&D. That being said, it's the rulebook for 3.5. I'm not sure what other kind of description/summary to write here.