It's kind of hard to review this movie without giving anything away to those who haven't seen it, (I'm sure there are a still a few) but I'll do my best to stay spoiler-free.
This may be the movie I was looking forward to most this summer (which is kind of depressing, since now I've seen it and there's still a lot of summer left.) I loved J.J. Abrams' 2009 Star Trek reboot, I thought he did a great job of renewing and modernizing the concept, while still keeping true to the original characters. Though I've been a fan of all the Star Trek incarnations, I don't really consider myself a "Trekkie" (or, if you prefer, "Trekker"), so I didn't have a problem with the changes made for the new version. I'm just fine with the time-travelling Romulans creating an alternate timeline for the new Star Trek - the new movies can make whatever changes they want without harming the continuity, since the original Star Trek exists within the original universe's non-destroyed Vulcan timeline.
In this sequel, the main villain is played by British actor Benedict Cumberbatch - you may know him from the BBC's "Sherlock." (And if you haven't seen "Sherlock," Netflix it or something, it's amazingly good.) Nothing adds weight to a character, especially a villain, like a British accent, and Cumberbatch does a great job without completely stealing focus from Kirk and Spock. Without giving away plot points, all I can say is there's cool spaceships, explosions, an all-too-brief glimpse of Klingons, and lots of witty banter between Kirk, Spock, Bones and Scotty.
Though I loved this movie, I think I loved the first one more. This one seems a bit long, some slow spots could have been edited a bit. The lens-flare effect was cool-looking in the original, but is now starting to get overdone. Don't get me started on the completely unnecessary cameo by Leonard Nimoy. (Does he have a contract with Paramount requiring him to be in anything having to do with Star Trek?) And not to give anything away, but hard-core fans of Gene Roddenberry's idealized vision of the future may have a problem with the less-than-ideal portrayal of some Starfleet officers.
But minor quibbles aside, still an awesome movie, definitely the best ride so far this year. I'm sure I'll see it many more times on cable and Blu-Ray.
But seriously, J.J., enough with the lens flare. You're giving me a headache.