I've never read them. I'm afraid the books would burn me. I've read in-depth reviews and analyses, though, and excerpts... summaries showing the characterization, etc. I know some people who have read it, but none of them are writers or English majors, and even they comment on the mediocre quality.

I particularly worry about popular-but-crappy genre fiction, because it just confirms what people want to believe - that all genre fiction is inherently inferior, because look at what the "break out" genre fiction is like! Likewise, every poorly written breakout inspires even crappier knockoffs of the crappy original. From what I've read, the Twilight novels actually bother me more for their commentary (and indoctrination) on people and relationships than their writing lessons.

Not to mention that S.M. publicly and profusely disavows having done her homework with regard to writing fantasy. Which, of course, she's not writing, really. Those vampires and werewolves are taken from fantasy, which is of course a ghetto of unpopular, badly written stuff for D&D nerds.