Already from the outset, this was easier to understand than the anime was. The series might be fond of throwing out chuuni bullshit left and right, but it will take time to slow down and explain.
I like how much the books work from the reversal of the usual Golden Age myth - in the past, everybody was much stronger, but it's because the past sucked and you had to be strong to survive, and very few people who actually remember those times want to go back there.
Felt like the book has gotten more serious than the earlier volumes - there was less of the usual silly shenanigans via Anos' parents and the fan union, but also less of Anos being over the top pompous. Not that the books had any less pompousness, since Nosgalia had enough to fill the void, but with villains it just hits differently.
And in the end, it's great that Anos is the demon king of tyranny, but all the way from the first volume, you can tell that what he hates most is tragedies, and he isn't using his powers for himself, but to help others. That makes his overpoweredness a lot more bearable than his power level would suggest.