Curious, there are 3 possible Lyonesse/Suldrun's Garden books to review, with different reviews on each one. Perhaps Amazon might consider addressing this.
This is without a doubt Jack Vance's most serious, mature work. He creates a fantasy setting of islands between Ireland and France set in the dark ages (post-roman), and offers a wandering, detailed and vivid story.
Some spoilers are in this review. Strongly consider whether to continue reading, as major plot threads may be discussed or deflated.
Initially the story mainly concerns itself with Suldrun, but before too long, she is gone and we gain other main protagonists, Shimrod, Dhrun and Aillas. Aillas' effort to find his son greatly resemble some of his other rambling adventure stories, with the protagonist moving from one setting to another. The journey of Dhrun and Gwyneth is similar, with Shimrod eventually joining them.
Antagonists are competent and developed as well, with Casimir being entirely too competent and ruthless for comfort, while Faude Carhiliot (sp) comes across more as a brilliant opportunist rather than a competent strategist.
I would need to check dates but it is possible this is the first time Vance developed complex and rational female characters in his story, particularly Suldrun. I have read this criticism of his work and in some cases it does appear justified (whether relevant or not is another matter), but I see no such issue in this series.
A major difference in Lyonesse compared to Vance's other works is that Vance's trademark humor, often deadpan or delivered in flatline the most outrageous or self-evident comments, is present but very subdued, and never does one feel oneself to be in a more normal vance story, where such humor can be a central feature. Lyonesse feels much more serious, and there is some doubt as to how things might work out for the major characters, particularly given that he kills his initial protagonist off so easily.
A fabulous story; I could nitpick but it is hard to find fault here.
Edit (9/26/07) Having recently reread the rest of this trilogy, I would say that this series is Vance's best. This is compared to Tschai, the Demon Princes, the Cadwal Chronicles, the Anome trilogy, and Ports of Call/Lurulu, plus whatever else I have forgotten. A major storyline is developed incrementally, numerous characters develop and many are discarded/killed in the course of the story, and a viable, and fairly complete, ending is provided.