Hmmm, the only reason I'm not giving this a 5, is that the fourth book in the series becomes almost too esoteric, even for me, a lover of esotericism, to digest.
I haven't read the Urth of the New Sun, the 5th book that is supposed to clear everything up, yet. I might revise my opinion once I've done that, but... let's just say my judgment has become a bit clouded by all the commentary I've by now read on the series and the religious flavorings that such extraneous commentary lends to the work.
I suppose that seeing The Lion Witch and Wardrobe series as being a Christian allegory now, didn't make me like that series any the less when I read it as a child; so why should the "New Sun" saga be diminished by something similar?
I'm not saying that it is thus diminished; the work is certainly too rich, dense and sophisticated for it to be a mere attempt at proselytisation, and one can certainly enjoy the narrative at many levels.
However, I think I might have to read the 5th book and then perhaps re-read some of the earlier books yet again, to get a better 'grip' on all that is being said and suggested.
This is not an easy body of work to wrestle to the ground. For those looking for hackneyed bodice-rippers, you will be disappointed, I fear. If you are looking for something that is original, and at times weird and thought-provoking, this is it.
New Sun often has one going: "Hey, wait a minute...."
Oh, and a warning to the wise; it is essential that you read the books belonging to the series in order, starting with the Shadow of the Torturer; more than any other series I have ever read, (perhaps even more so than even LOTR).
The first 4 books of this series should be read as if they are chapters of one book, because they are all indispensable to one another; you cannot really judge any of them on their own merit (though to me SOTT was probably the most satisfying as a standalone out of all 4)
I also think that the series was written with one of it's goals being that it should be re-read. Severian even says at the very end: "Have I told you all I promised? I am aware that at various places in
my narrative I have pledged that this or that should be made clear in
the knitting up of the story. I remember them all, I am sure, but then
I remember so much else. Before you assume that I have cheated
you, read again.
It is in this volume that the postmodernist character of the New Sun cycle most clearly comes into focus, with so many dualities and pluralities and facets breaking into a rainbow of views that deconstruct it's own origin that it makes your head spin.