Just in case the next sentence doesn't make it clear: THERE ARE SOME SPOILERS HERE.
I just got back from watching it and here's the run down:
Plenty of solid action.
Great special effects.
As far as a movie with aliens go, it's pretty realistic. The aliens weren't invincible, just hard to kill. They weren't mindless killing machines, either. They pulled their fallen comrades to safety and retreated when necessary.
It was cool to see the war raging in Los Angeles instead of a third-world country that I care less about than what I leave in the toilet.
The trailer lied. 98% of the movie is shaky-cam.
The cuts happen way too often. The average shot time couldn't have been more than 5 seconds.
Too many tight shots. Most of the action shots were from a perspective of maybe 10 feet away. You miss so much.
Fuck you Saving Private Ryan! That was a very successful movie that, unfortunately, made every director in Hollywood think you have to shoot every military movie just like it, outlined in the previous three points.
The audio blows. The foley artist should have been fired. There are way too many shots where you couldn't hear the dialog above the environmental noise.
Cliché-or-rama. There were several clichés. The worst of which is the "We can't remotely detonate the explosives that we just planted!" That has to be one of the top three clichés. Not only that, but they did the "I'm mortally wounded, so I'll blow myself up to save you!" easy out. Talk about lazy writing.
Not enough aliens (Ha! Bet you never thought you'd hear me say that!). There isn't one close shot of any moving alien, only the dead ones. Even then, it's usually done in poor lighting. Only long shots or right-up-the-anus shots that only last 1 to 2 seconds.
Way too many soldiers die. Yeah, it's a war movie, but when so many die so early in the movie, it loses its punch and becomes annoying.
The pacing was somewhat bad. It tented to stutter, making the movie drag on and feel awkward at times.
The short version: catch it at manatee if nothing else is playing or catch it on video.