Not yelling at you or Kristen, I'm blaming the scrip. The guy who wrote Death Wish 3 (perhaps the most unintentionally comical movie ever) could've done better at times. I don't think that Melissa's style was exactly cut out for fantasy romance movies, and she deleted somethings that should've been in there, and added stuff that wasn't really necessary.
Catherine and the actors changed some things in Twilight, and Chris and the cast did the same for New Moon, and I'm betting that David and the cast made changes to the Eclipse script too. At times, I think that we'd have been better off if Stephenie co-wrote the script instead of just taking story credit.
However, considering some the crap that she's been given here, and in some of her other movies, Kristen has done an admirable job.
I mean, we can nit pick all we want about Kristen vs Bella--Kristen has green eyes (brown contacts), dark blond hair (hair dye, wig, or both depending on the movie), is 5'6" and has a personality that is unlike Bella's as it is like it, while Bella has brown eyes, brown hair, is 5'4" and has some similarities to Kristen's personality. But if we like what's on screen, why should little details matter?
I didn't imagine Bella being very feminine--Kristen at times has been more feminine than Bella, and that's a woman who used to have an aversion to dressing up and wearing make up--hence, I didn't think that she'd have an extremely feminine voice.
There are more places that little things are more glaring--Ashley Greene is 5'5" while Alice is 4'11" or something like that.
I do feel that Kristen Stewart is about as close as they were gonna get to someone who could look like a convincing Bella and still be a good enough actress to make a reasonable film out of a crappy script. And if you need convincing on Kristen's acting abilities, watch or rent Speak, though it seems that you don't need much convincing
And to those who don't like Kristen, you're stuck with her for the last two films and most of the people who hate/dislike her is because she's dating Rob. I don't get people like that, and Rob has had to stand up for her so many times--without her asking--that his you know what probably doesn't know what a chair feels like (speaking figuratively, of course).
At least Kristen and Rob haven't let a few crappy "fans" get to them, because even though Kristen has a bit of an aversion to taking photos with random "fans" that pop out of nowhere (the ones who post the subsequent photo on Facebook or Twitter and make fun of her, or sell the photo to the tabloids), she's never turned down a photo or an autograph, especially to true fans of her and the series.