I'd seen this before, and back then, I'd have given it a 4, but once again, if you go into this with the right perspective, it makes it far more enjoyable to watch. One of the reasons this film is so amazing is how it is crafted to keep you thinking about it and analyzing it long after the final credits. The most obvious element used to this effect is the unlinear story progression: the stories aren't shown in chronological order, which leaves the viewer piecing together what happened and why this character is wearing that or how that character could be there, and so on. The way this is done is, frankly, masterful. Then you've got a few more elements that are mysterious and are the basis for many crazy theories on the web.
And of course, this being Tarantino, the dialogue here is absolutely astounding and perfect in tone, delivery and content. The acting is also fantastic, especially from Jackson and Travolta.
On the other hand, this is a movie you either love or despise. The subject matter is easily offensive, and there is no actual point to it all other than telling a story. Also, many different filmmaking styles and pop culture facts are referenced, so someone that isn't well-versed in such things might miss the point of the film entirely.
In a sentence:
A movie you will either love or despise: either the genius writing, storytelling, pacing and acting hook you in and keep you thinking about the movie for ages, or the pop culture and stylistic references fly way over your head and you get annoyed by the particularly crude subject matter. It's up to you.