I agree with you and Amanda (who disagree, isn't that funny!?). I loved this series because the stories were interesting and fun but, most importantly, accurate to the mythology, which made learning about it again (a refresher from my college mythology courses) exciting. I'm with Amanda, though, in that I saw very little character growth in any of the books, until Book 5 where there was just enough to seem different. This seems to be the same in all Riordan's series' (I'm reading his Heroes of Olympus and The Kane Chronicles as well), so it's something I just have to set aside because the fun and interest of the stories are still worth dealing with flat characters. Which is saying a lot, because characterization is one of my biggest "things to look for" in a book - I guess that just goes to show you what a great entertainer Riordan is.