I think Peter Jackson could have cut out the Jamie Bell subplot stuff to improve the running length somewhat. But that said, it never seemed to drag. The scenes that took their time (eg the kong/anne scenes) were usually the ones that were the best. That said, I doubt I could sit through this movie again without drinking half a bottle of coke first, my eyes just get tired after a bit.
Would cutting out the Jamie Bell stuff and editing half an hour or so out of the movie make it a better film? Doubtful. I'm struggling to think of how this movie could have been better. The last 20 minutes gave me some serious vertigo. The sfx in the last 20 minutes were amazing, considering most of it was cgi. How cool was that slow motion shot as King Kong fell down the Empire State Building? Woah.
Oh yeah, I heard people dissing the effects in the movie. I totally disagree because the effects here ranged from excellent to perfect. I'd heard the brontosaurus stampede had some shit effects so I watched that bit more intently, and there wasn't anything wrong with it. The dinosaur effects in Jurassic Park and Jurassic Park 2 are more realistic but that doesn't make King Kongs effects any less stunning.
Oh yeah, one dodgy effect was the greenscene use when Carl Denham was filming that scene on the ship deck. But that's all. Besides, I thought it kinda looked like a throwback to the 50's style sfx with screens, so it was FINE.
Anyway: great movie. 9/10. Oh yeah, those native people were scary as hell, and Naomi Watts is a damn good actress, her performance totally lifted the movie. And Jack Black and Adrien Brody were good as usual.
Finally, I wish King Kong was real, because he was a great character in this and I liked him.