I recently re-read the entire Codex Alera series, mostly to look for hints of things that I didn't see coming. I think the timing was pretty good; I remembered very little about what happened. That is to say, I remembered most of the broad sweep, but very, very little of specifics.
And I think I found mostly what I was looking for. I missed most of the hints about Tavi and Kitai, the first time. And the other big one that I was specifically looking for was Isana's treatment of Tavi, especially in the first book.
I thought the hints dropped about Tavi and Kitai were pretty cool, and well done. I definitely felt like I should have seen it the first time.
The parts about Isana and Tavi was a bit less cool. We have Isana's point of view a number of times in the first book, and she thinks specifically about Tavi a couple of those times. And there should have been a broadside about their relationship (after all, she's thinking to herself about him; she doesn't need to guard her thoughts), but there wasn't. So that was a little disappointing.
And linguistically, the book was a bit of a mess, with quite a few non-Roman names, and the weird use of House Gaius (putting a praenomen into a family name). There was also some gender confusion, such as Placidus Aria (instead of Placida Aria). I might well have remarked on it before, but there was a big hint about Tavi in there (Tavi not being a Roman name, of course).
But the books held up quite well on second perusal. It wasn't quite as hard to put them down, but it still wasn't easy.
And there were some interesting things I'd missed. The herdbane tribe humans who could jump fifteen feet (I read that as using the birds to get that high in my first reading. Also, think of that in terms of dunking a basketball: I've heard of a couple of people who could dunk on a twelve-foot net, but nothing higher than that. And this was a whole tribe of people who could do it). The archers shooting arrows six hundred yards. I actually doubt that this is possible, even with machine assistance. I suspect wind resistance will slow the arrow down too much, no matter how much force is behind it. Certainly, I've never heard of shooting an arrow more than about three hundred yards.
There was also the legions who could march (on a furycrafted road) one hundred leagues in a day. That's at least 30mph, sustained over an entire day. I hadn't worked out how much Butcher was tying himself in knots on how fast the ships on runners were going. And I think it was trying to square it with that marching speed that made it such a mess.
Regardless of all that, it was still a very good series. I don't think I'll re-read it again any time soon, but it was fun doing it this time. It did mostly hold together.