It's sometimes interesting to look at a novel in light of an author's whole career, and see themes that the author has played with through other novels. Roger Zelazny's first novel, for example, This Immortal, attempts to put the mythical into a science fictional context, just as later novels like Creatures of Light and Dark and Lord of Light. It also showcases his interest in the different voices a narrator can have, as he moves from a register that's straight out of Chandler to a more epic voice and then back again, often within the space of a few paragraphs.
In this novel though, as in Dream Master, written around the same time, he's more allusive than in the later novels. Is Conrad supposed to be a satyr, or even Pan himself? Maybe he's a sort of hero out of the collective unconscious -- he shares a number of attributes with Oedipus, for example, as well as Hercules. In the later novels, those correspondences are more explicit; for example, in Lord of Light Sam is clearly Buddha. On the one hand, it's cool when an author leaves a lot for readers to figure out, but at least in Zelazny's case the later novels are much better and more cohesive.
The oddest thing about this novel compared to Zelazny's other output, though, is the almost pointlessness of most of the plot. Zelazny's heroes usually buck the system, and often are at least partially successful in overthrowing it. Although Conrad is also a rebel, it turns out that most of the plot would have been the same without his presence. Although that's sometimes an interesting direction to take, I think that here it's a serious weakness. There's a lot of bluster and action to convince us that something is really happening, and it's almost as if Zelazny realizes that if he lets Conrad free into the plot, he'd just wreck the whole thing. It's in the later novels that he figures out how to put a powerful character into a plot and not have it be completely unbalanced.
On the opposite end of the spectrum, Solstice Wood comes late in Patricia McKillip's career (fortunately, she's still writing, but she certainly has a lot of books behind her). One theme she's returned to often is the idea of someone like Tam Lin who wanders into fairyland and is trapped there. She's had various takes on this idea, including more metaphorical ones such as a character trapped in his own unconscious, and it's been a fertile ground for her. Solstice Wood gains some of its resonance from all of those other books, as it somewhat turns them on their heads. Here, we have a sewing circle who uses its magic to enforce the border with fairyland, so that the fairies can't get over and kidnap any people.
But it turns out to be more complex than that, because the fairies are like people; some are good, some less so. There could, in theory, be a cultural exchange that benefits both sides, rather than the hostility that has held sway until now. Now that I see it in cold print, it seems pretty silly, but, as usual, McKillip's skilled prose makes any story worth reading.