I read these books for the first time a while back. I'm guessing around 2008. I enjoyed them back then.
Most of the time, when I try to visit the books that I enjoyed when I was younger, I find that they lack the "magic touch" that used to draw me in, and made me love them so much. I think that it's mainly because I no longer have the ability to emphasize or emotionally connect with characters - it's a skill that I've lost over the years.
However, that being said, I still really enjoyed this book. Sure, the writing style is simple, but I think that makes it all the better. I mainly picked this series up because I haven't been feeling too well lately, and needed something that wasn't too dark or depressing. Yeah, these books still have dark themes, but they have relatively happy endings, and aren't overwhelming to me.
I own this whole series, so I'll be reading the rest of it in the following weeks. I also own the first book to The Heroes of Olympus, and I'm looking forward to acquiring the rest of and reading that series as well.