I re-read The Fifth Head of Cerberus and discovered that what I'd thought was the story was only the first section. And that I'd either forgotten or missed a lot. So...
Reading the New Sun again was like reading it for the first time (except for a bare handful of scenes I remembered). I suppose in my defense reading volume 1 one year and volume 2 a year later isn't conducive to making connections, and by the time the 4'th book came out the first was pretty hazy. Especially when distracted by grad school and babies.
It was weirder than I remembered, creepier than I'd remembered, and with more layers in it than I thought. It follows the story of Severian, a journeyman in the Guild of the Seekers of Truth and Penitence, told from his own (not perfectly forthcoming) point of view as the eventual Autarch; set in a very distant future with a failing Sun and cooling Urth. I have
not read the "coda" that ends the series.
The series is, of course, a science fiction adventure, but with so much allusion and mystery and even allegory that it is challenging to read. Which isn't quite the right way to describe it--you can read it straight through without bothering about the details or the inconsistencies, and follow it OK. Except that what you think was happening wasn't always quite what was really happening. Mystery writers drop in little details that you should pay attention to--so does Wolfe.
It is well written--far better than much of the modern fiction I've read--but I won't say "read it." Some friends would be put off by the unpleasant nature of the protagonist, or by his dealings with women, or by who his companions turn out to be; and I can't fault them for that. If (Heaven help us) someone ever tied to make a movie of this it would be a horror movie.