First off, this mini review is based purely on the 3D BluRay version.
Secondly, why a lot of people are here in the first place is to see how good the 3D element is.
To cut things short, there is virtually no 3D. I have 7 3D movies in my collection and this is by far the worse one... in fact I would go as far as saying it is NOT 3D!
Thirdly. I am a massive Jack Black fan, I'm almost a fanatic! However, this is the worse film I have seen him in. There were a couple of really funny moments, lol one moment (when he has a wee!!!). The movie is a 4.5/10 for me.
My Amazon rating is purely based on the virtually non existence of 3D, but even if it had more 3D it would only get 2, 3 at the very best(some nice vibrant colours in movie + I have seen worse movies).
Animated movies, and Avatar are the only 3D movies at the moment that have impressed me (I'm hooked on 3D gaming on my PS3 though!).
If you must have this in your collection, then I wholeheartedly recommend buying the 2D version if you can get it much cheaper.