Oh, the Iranians aren't pleased about the movie. Both the people AND the government. Personally, I think that they can go stuff it. It's a movie based on a comic book. Geesh.
That being said, the battle DID happen, and the Greeks did end up kicking ass at Plataea. Sure, the Persians were very stylized in the movie - but did the movie really portray them in a way that wasn't somewhat accurate? I'm sure that the forces of both sides pillaged entire villages and mutilated some corpses. As for Xerxes not being a ten foot tall transvestite - alright fine. However, he was off his rocker (God-king bullcrap), and I'm sure there was all sorts of debauchery going on in his private tent. There probably weren't any goat people, though.