Reading all of the books in quick succession shows just how repetitive Brashares' writing becomes. I think I read that sentence about being able to adjust to anything 17 times in the course of 4 books. She also has a weird tendency to exotify Asian things and every use of "women of color" in the book bothered me.
Overall, I found the characters quite annoying in this book until the ending, which saved the story for me (mostly). As a teenager, I think I related to the characters a lot. I was going through the same things they were, but these are books that were really written for teenagers. As I am no longer a teenager, I didn't really get anything out of them this time around.
Now I'm off to finish the series. I'm almost the same age as the characters are in Sisterhood Everlasting, and I'm very interested to see how I feel about the book now.