The score was very John Williams-y at times, especially when Magneto's moving the sub over to the beach.
If anyone follows me on Facebook, these comments may seem familiar, but I'll expand a bit on what I wrote there:
The first hour is REALLY dodgy and had me nervous, but it picks up and the last 45 minutes are flat out great. McAvoy and Fassbender bring real nuance and layers to their characters, and most of the rest of the main cast do admirably. It's not great, but it's the best of the series so far.
Also, it was SUCH a relief that two of the biggest question marks for me (the two unknowns playing Havok and Banshee) turned out to actually be two of the better actors in the movie. The kid playing Banshee especially was really good, and seemed really natural. I hope they get more work after this.
Also: I love the very last shot of the movie for two very special reasons. Two very pointy, special reasons. SPOILER: Tiny horns! Tiny horns!
January Jones is such a bad fuckin' actress.
Seriously, you have a guy like Michael Fassbender with no lines and in the background, and he's still imbuing the scene with a sense of unchecked menace and machiavellianism. Whereas Jones, you could literally replace her with a mannequin in all her scenes and the emotional weight of them wouldn't be affected for a second. It's anti-acting. I have no idea why she's so popular.
Continuity-wise, the biggest hiccups I noticed are that Magneto DIDN'T help Xavier build Cerebro, and it they didn't meet when they were teenagers.
Everything else was explained (Mystique ages slowly, and even if they didn't touch that you could just assume she manifests herself as younger) or fits easily.
Yeah, it seems they're full-on enemies by the end of this movie and claim that contradicts the Jean Grey recruiting scene, but there's still almost 25 years of history between where this film ends and that scene takes place, so who knows if they made amends even temporarily?
What else is there? Havok is now Cyclop's older brother instead of younger? That's easy enough to swallow. You got Mystique in Azazel's presence, and plenty of decades for her to have a tryst with him and pop out baby Nightcrawler.
Honestly, if you ignore "X-Men Origins: Wolverine" (which it seems has been jettisoned from the X-movies continuity already), there's not much of a problem. Moira could easily be considered in her mid-to-late-20's here, and we didn't get THAT good a look at her in X3, so let's just assume she's in her late-50's there. If that's the biggest continuity plot hole, that's not much.
I loved the three cameos, and while I'm disappointed the big one was spoiled for me, I didn't know the context ofthe scene so that was fun! The other two were nice touches as well, although now that I think about, one of them isn't so much a cameo as it is a subtle nod.