And now a dissenting opinion from someone you don't know.
I disagree. Spend your cash on it.
It was incredible at parts, but...
Too long. Towards the end I started to get a bit bored.
The music was horrendous. The use of source music was terrible. All Along The Watchtower.... Really? "Two riders were approaching..." as we see two guys walking in the snow up to the base... REALLY? I am rolling my eyes as hard as I can.
Hallelujah by Cohen? PLEASE. You couldn't at least use the Buckley cover? I know its the original, but it made that love scene laughable. A gospel choir coming in while they are having sex? Its just stupid. I blame the director.
And the original music sounded like a horrible 80s cop movie. I felt like I was watching an Edgar Wright film making fun of such cliche music. That crappy delayed guitar drove me nuts.
But...
The non-linear story is done in a really interesting way.
Shot well, looks beautiful.
Its an incredible story, written very well (even if parts of the dialogue do not successfully translate to film. Comes off a bit cheesy.)
There are some awesome action scenes. (and extremely violent)
Speaking of violent...Rorschach is sooo hardcore awesome. Worth the price of the ticket alone.
Ending is better than a giant squid attacking NYC. (which is how the Graphic Novel ends)
Silk Spectre II is so freaking hot. I mean...dang.

I agree that the political stuff doesn't work so well.
Really this is two separate films.
The interesting film is the one about the characters and them having to deal with their past. (because they are being targeted).
And the other much less interesting film is the more epic political/nuclear war/nixon stuff.
The stuff that it gets right. It Really gets right and its awesome.
The stuff it doenst get right isnt terrible (except the music), its just is so noticeable because so much of the film works really well.

That's my two cents.