I found this nearly unwatchable, indeed, I'm not sure I have paused a movie in Tivo so many times to go do other stuff. If you're a fan of cringe-inducing embarrassing moments this may well be a fantastic movie for you. If you're like me and find these kind of things not so much funny as sad or painful, probably not.
I watched it largely on the strength of Holly Hunter and Kathy Bates, two of my favorite actresses. Kathy is fine, but is not really a main character. Holly gets a lot of screen time and gets to play an interesting range.
If anything, what I'm calling the fourth act makes it all (possibly) worth the wait. It's an exciting, nasty turn, and for me it was the payoff for what would otherwise be unmemorable. The fifth act is a pretty standard wrap-up.