This book is one of the things that got me interested in fantasy to begin with. There were others - Donaldson, Lewis, Vance, Zelazny - but this series was among the most accessible. I wasn't (at the time) impressed by McKillip's earlier work, but this book in particular made a lasting impression on me. I've re-read it a few times, but not visited in some decades now. I saw Ace's omnibus volume, and thought I'd go back and see how the story has stood the test of time.
Quite well. McKillip's introduction seems dismissive, and it's true that the book lacks some of her usual (perhaps later) finesse. The seams are visible, and there's a certain meandering repetition - he wakes up from dreams a lot, he decides to go home a lot. Overall, Morgon seems more anxious and neurotic than I recall, less light-hearted. But the magic still works.
The world is fascinating, but a little clumsy at times. There's a lot of magic lying around - the Wind Plain and its ruins seem a clear fore-runner to the Bone Plain and its tower in a later book - but its all ancient, it's origins buried in history. Most people seem normal until Morgon begins actually meeting them. Then, it seems everyone he meets is old. This ruler? 700 years old. That person? A thousand years old. Even the first time I read this I remember wondering, "No one knows what happened back then, but wait - almost everyone he meets was already alive ? That doesn't make sense." It doesn't, really. The later books try to make it work, but it's better glossed over. And the book works despite it all.
The Riddle-Master of Hed isn't quite as perfect as I remember it. And some of McKillip's references are a little more visible to an older eye - a pigherder turns up a lot - but it's still a great book. I heartily recommend it to anyone who hasn't already encountered it. This isn't a classic to read because it's old, but because it's a lot of fun.