Given all the recent fuss, I picked it up again and found:
1. It was more boring and less analytic on matters of public choice than I had been expecting.
2. Although some of Hayek's major predictions have been proven wrong, they are more defensible than I had been expecting.
3. The most important sentence in the book is "This book, written in my spare time from 1940 to 1943…" In those years, how many decent democracies were in the world? How clear was it that the Western powers, even if they won the war, would dismantle wartime economic planning? How many other peoples' predictions from those years have panned out? At that time, Hayek's worries were perfectly justified.
4. If current trends do turn out very badly, this is not the best guide for understanding exactly why.
It's fine to downgrade the book, relative to some of the claims made on its behalf, but the book doesn't give us reason to downgrade Hayek.