I went to this. The girlfriend and I both thought it was pretty lame.
I can't say anything about comic accuracy because I've never read any GL comics.
I thought the opening scene with Abin Sur was pretty cool and I really liked the guy who played Hector Hammond. That's about it.
Ryan Reynolds played his usual character.
The lantern powers just seemed really childish... he'd make a green sword, or a green shield, or a big green fist, or a green race car. I would've come up with more entertaining giant green things to beat my enemies with
And the final battle was weak as shit.