There are SPOILERS for the first two books in this series, so read at your own risk.
Getting inside Annabeth's head was the most interesting part of this book. I liked returning to some of my favorite character's POV's, too, but she really took the cake with this one. I've never been the biggest fan of her character (not sure why, we just didn't click) but this made me such a fan. Her solo quest really spotlighted what was so awesome about her. Her ingenuity and brains really made me respect her character.
This book is my favorite in the series so far. It was also the funniest. I was laughing out loud the entire time, mostly thanks to Leo and Coach Hedge. Surprisingly, it was the most romantic book as well. Romance has really been played up in this series, compared to how it was in the Percy Jackson series. Every time a couple was together on the pages I was fingerling inside and cooing over the adorableness. Percy and Annabeth were the best, in my opinion. One of the best relationships in all of the books I've ever read. There's both a depth and a natural chemistry to them that just makes them so great to read about.
The hardest part of reading this was the amount of character names. I started getting them all confused, even when I shouldn't have. But it's just so many characters running around, many with their own POVs, and getting my head wrapped around it was incredibly hard. Normally I have no trouble (I read a lot of epic fantasy where there are twice as many main characters). I think that a lot of the personalities were similar, though, and perhaps that messed it all up in my head.
I knew how this book ended going into it (my friend needed to vent when the book first came out) but still found my heart pounding. It's a major cliff-hanger and it had my heart racing and my eyes tearing up. The descriptions were so cinematic I felt like I was actually there.
So definitely read this book. It'll break and mend your heart; make you laugh and cry; and all around satisfy you. Here's the link to add it to your goodreads shelf.