I liked LH and SoN, so I'm not complaining. But I did feel something different about them, especially SoN, LH actually had a little more PJ feel to it I think. Maybe, the books just feel so different to us because we haven't been able to see them as a whole. LH was one side of the demigod spectrum(Greek) and SoN was the other side(Roman). Maybe in Mark of Athena when we get to see all the characters together and the camps together, it will feel more complete and like PJ. Or maybe it's the fact that Percy is older now and has lost his novelty to the world of myths and monsters.