I prefer the Kane chronicles because of the way he writes it from the perspectives of both main characters. That and it's a bit more epic than his other series in what the people go through
I have to say The Kane chronicles, they're just more interesting to me. I also have had enough of the percy jackson world, but the second Heroes of Olympus could be good.
I liked the Percy jackson quite a bit, I haven't read the Olympian series, but my favorite was The Kane Chronicles, as Baudin said, and I find the Egyptian gods slightly better.