I finished twisted a few weeks ago but never got around to posting about it.  I liked the book it was good but not as good as speak.  I think it was partly that it was from a males perspective. Tyler is a typical teenager and think that was what made me not like him.  The story itself was very atypical. The nerd goes through a dramatic transformation and the popular girl falls for him.  The book was stereotypical and not as gripping as speak.  That could be because in speak you don't know what happens to melinda until the very end.  Unlike with twisted where it is all layer out in the beginning of the book.
One thing that Anderson is very good at is the craft move of describing a character.  Such as "Mr benson, my probation officer was a big guy, ex-marine plus sixty pounds,gray in his buzz cut, thick glasses, and a smile that reminded me of a hungry possum." She is god at giving you a mental picture of what her character looks like.