Continuing the full re-read. This ends up as a strong 4.5.
I had always previously considered this one to be the weakest of the series. That isn't saying much, to be honest, when the whole series is very, very good. Usually I would kind of skim through the last third but a more careful re-read this time showed me new nuances.
I had always felt that the historical exploration had overshadowed the plot somewhat, which is why this was a weaker one. It still probably does, a bit, but this definitely rewards a more careful read.
Full series recommended, yes, yes.