The Percy Jackson books were OK for me (my son and daughter both really like those) and this was described to me as “Percy Jackson but with Egyptian myth.” And it kind of is, but I liked this one a little better.
I did not care so much for the device of alternating chapters between the Kane siblings, Carter and Sadie, recording the events of the story for you to “listen” too, as the narrative unfolds in such a way that you wouldn’t tell it that way if you were recording it, but I don’t think a kid’s really going to notice or care. That said, that did allow Riordan to develop two main characters really well. Carter and Sadie are both quite distinctive, with both having important roles in the story and not being in the shadow of the other (eg, neither cliche of Sadie being overshadowed by her big brother or Carter is outdone by Girl Power of little sis is present here). Each needs the other’s special skills and abilities.
Overall, this will be a great read for kids and a nice “in between books” read for adults (actually, it’s much better than a lot of adult level books you could read). And while it may look thick, the chapters move quickly and the final battle (there’s always a final battle) will keep you turning pages.