In general, I must say that I liked this film overall; the political subplot, which I want to specify was not in the comic, was horrible, but other than that... the work is faithful to the comic, except for a few inventions, like the orcs, the leprous samurai-style immortals (in the comic they don’t carry katanas), and it’s nice to see how the panels are reconstructed and animated in an absolutely faithful way.
Regarding the pseudo-fantasy inventions, the transsexual effect, and the disproportionate number of Persians, upon reflection, I don’t view it so negatively; I suppose that for the era, an army like the Persian one would have had the same effect on people like the Spartans as the represented army does on us in the film, a huge thing; just as orcs and such peculiarities are things that do not exist for us, fantastic monsters, for the Greeks things like elephants were the same; in the end, I see the inventions as an interesting proportion between the perspective of the modern viewer and that of the Spartan.
However, I don't think a message, war-mongering or not, needs to be sought after; it’s epic, beautiful, and good; there’s no pretense of minimal historicity, the comic itself was loosely based on Herodotus, who clearly invented some things; it may be true that the Persian Empire was one of the most peaceful empires, but that's not the important part; therefore, the accusations of pro-Nazi sentiments, Americanism, etc. are out of place (by the way, 300 losers against an empire of lazy, slimy, money-driven people with spectacular modern weapons sounds more like terrorists against Americans—not that I defend terrorists, but if we are really to put it in a modern context).
In essence, it’s a film superior to certain films with pretensions of historicity, like Alexander, The Crusades, or Gladiator, which only manage to be a great boredom rather than a great historicity.
As for the declamatory phrases, I liked them quite a bit; it felt like reading a typical version of Greek, they uttered so many clichés that in the end it was even amusing... "I brought more soldiers than you!" XD
Anyway, the comic remains superior, even if a bit pricey ;) The film is not a masterpiece, but it’s not the horror I’ve heard people talking about either, absolutely!