I liked Madouc more this time than the first time I read it. Still, it failed to work the usual Vance magic on me. Effectively, it mostly provide more of the same (as was in the first two books). Usually, with Vance, that's more than enough.
I'm not sure why I was ... not dissatisfied, but complacent. This book leaves most of the politics that made the first book a little slow, and concentrates more on human stories. Perhaps it's simply that I didn't take much to Madouc herself, though it's not so often I actually like Vance's protagonists. Perhaps it's a certain young adult (as when Madouc name s the stable boy Sir Pom-Pom) feel that didn't match the rest of the book. On the other hand, I did enjoy struggles with ogres, etc.
The fairies play a larger role in this book, but by now I found them a little on the tiresome side. Vance brings in the Holy Grail, and that may have been too much. I think, largely, that the series, in this book, simply goes on too long. Even Vance himself seems to hurry to end this with a fairly long end section that tidily wraps up loose ends, but nonetheless seems rushed.
All in all, pleasant and readable, but not really enticing. If you haven't read the first two books, this one will not really stand alone. If you have, by all means read this one. There's nothing wrong with it - it's just not great.
All in all, I'm glad I re-read the trilogy - it's better than I recalled it being. But it's also a long way from being the best of Vance's work.