As for the naval battles, if you're the sort of guy like my pal Broos who'd be all, "Yeah, I know my naval history, I've studied it well, written nautical adventures, and can't wait to see such things accurately reproduced onscreen," then...no. Just no. You'll be mad at me if I tell you to see this. These are naval battles for people like me who do not want to think about how the real-life circumstances affect the physics or whatnot; the ones where horses can suddenly show up and just jump from ship to ship -in the sea, mind you - busting shit up. Naval battles of ancient Greece in which giant mutants operate flamethrowers. Those kinds of naval battles. Also, there are sea monsters.
If it sounds like I'm insulting this movie, you are reading my tone wrong. I understand that all these things I say would, in the hands of some imaginary tut-tutting urban cinephile, be considered demerits; they are all positives and plusses in the topsy turvy world of 300. I would have liked a more coherent plot with Xerxes more active, it's true; and the lack of a clear device, as in the first one, to tell you "this is storytelling, and not necessarily the way it happened" is an unnecessary slip-up (Gorgo narrates most of the movie in flashback, but not all of it).
The battle was fought over a long period
But given the right mood, I do not tire of head-crushings, 3-D arc-shaped ejaculations of blood, water and arrows thrown in my face and plenty of Eva Green. If you don't go for the 3-D Imax version, you're cheating yourself - the only point of this movie is to take everything over the top, and that should include the viewing experience (if they could figure out a way to throw water on you in a theater, it too would be appropriate). I can't decide if it's more homoerotic or more homophobic than its predecessor - it will surely be read both ways. And it's the closest thing to a GWAR concert you're likely to see in a major theater chain.
Part 3, if it happens, can only top this by featuring an all-out orgy scene. I look forward to that.