I'm in agreement with CCL...since vampires aren't real, their nature is open to any interpretation the author wishes. Personally, I hated Anne Rice's vampire books (though I loved her Mayfair witches series, even though they didn't wear pointed hats and ride brooms. )
I liked this series because I felt it was fresh and original. I don't have any real criticisms of it - it succeeds admirably at being an imaginative love story and as a crossover novel for tweens and adults. I think describing it as sexist is way off the mark - the female vampires are as strong and "talented" as the males, and Bella ends up as the strongest of them all. As far as Bella's character goes, I am probably in the minority as liking her depiction as a sulky introvert. (I also thought Kristen Stewart perfectly nailed Bella's personality in the movie.) It could be that I'm tired of the sugary Disney females that are on constant parade on the TV at my house - Raven, Hannah Montana, iCarly, etc. I agree with PWS's take that Edward's "controlling" aspect has much to do with the fact that he is literally a very old soul in a teenager's body, as well as the Romeo & Juliet comparison. It's pretty normal for young women to fall in love with the idea of a perfect romantic couple. It's not realistic but Meyer didn't invent the concept - most young adult lit ends with everyone being happily paired off. Even Harry Potter ended up finding his soul mate.
Now, I didn't love absolutely everything about the books - I didn't like the "sparkling" either, and I'm well aware that the writing isn't in Pulitzer territory. But I don't like the implication that if the story doesn't adhere to some vague politically correct guidelines for young adult literature that it's unhealthy for kids to read it. It's an engaging fantasy series and I gave it to my daughter to read without any qualms whatsoever.
I agree that in taking literature as an art form, taste is subjective and personal. Speaking for myself, I can take as much pleasure from the Twilight series as I can from Jane Austen. I bought all the books as I'm more than happy to support a successful female novelist and a former FORT writer.