I wasn't a huge fan of If I Stay (you can read my review here), but I guess I cared enough about the characters to see how their story ended. I had to wait a few weeks since there were a few people ahead of me in the library's holds queue, but it wound up being worth the wait. Most of the things I complained about with If I Stay weren't present in Where She Went. I think that's mostly because Where She Went is 1) told from Adam's perspective (so the Mia whininess is kept to a minimum) 2) three years after the accident (so they're not teenagers anymore, so there's that, too). Meanwhile, the things that made If I Stay great continued to shine, namely, Forman's ability to balance past and present narratives in a cohesive manner and her delicate crafting of characters and their relationships.
The ending was still sort of cheesy, but you can't win 'em all. 4 out of 5 stars.