this movie had some problems which i attribute to the direction, lighting and editing. the most obvious "for instance" would be the first time you really meet a devolved vampire creature, which could totally have been an awesome, epic, classic moment in movie history, but was just poorly executed with uninspired camera angles, editing and lighting.
these sorts of issues are pretty consistent throughout the movie, but once you accept these sorts of problems, the movie on a whole is decent enough to still watch and enjoy.
it has some very reliable players including willem dafoe (love that guy), sam neill and ethan hawke who, while i have never been a huge fan, does qualify as a reliable actor.
daybreakers brings you an interesting story, likable characters, an unbelievable and poorly explained but still interesting and intriguing back-story, cool scenery and atmosphere and some cool monsters in a story that ends nicely and leaves you feeling content despite some of the glaring malfunctions in the execution of the movie as mentioned in the first sentence of my drab, ambiguous review.
i say check it out.
i'm not even much of a vampire fan and i dug it, so if you just looooooove you some vampires then you will probably be able to dig this movie despite it's short-comings.