IDK, I love them as well as the Olympus series - tonally they are very different books. I'm read them all with my son (in fact all the original Percy books and first Kane books are all autographed by Rick himself )
I've read the first 2, good, but not as good as the other Olympians or Heroes of Olypmpus.
but it's OK and book #3 is out. It's OKnot as good as the other Olympians or Heroes of Olypmpus.