It's hard to screw up a story such as "The Iliad", but the movie almost did. I liked the cinematography, the landscapes and the overall experience (including an interesting if somewhat repetitive use of music).
Some performances were great (Hector, King Priam) some were good (Helen, Paris, Odysseus) and the most important character was not entirely believable in my opinion: Brad Pitt's Achilles.
I never felt any empathy for the character. There was not enough characted development even after Priam's visit. Also, we never got to experience the emotional bond between Achilles and Patroclus, which is the reason why Achilles went back to war in the first place. I felt that they knew each other but not that Achilles' sadness was enough for him to make that momentous decision.
Also, I think they downplayed the desecration of Hector's body and that is an important part too because it links back to Achilles' relationship with Patroclus.
In summary, I got what I expected but not more...