I've read a few other books by Wilson, and I liked them all, so when I saw this one, I was hoping this would be good too. I was not disappointed. Wilson does a good job of telling a difficult story.
The most impressive thing about this story, I think, is that it doesn't really make a lot of judgements. The story focuses on people who decline the Travellers offer of immortality, but it doesn't give the impression that they are any better than those who accepted the offer. It also doesn't fall into the boring cliche of the benevolent aliens who save us from ourselves. It does a good job of presenting both sides without making any assumptions about which is right or wrong, or whether either is. This makes for a much more enjoyable story, and I think that is what I like most about Wilson's books overall, is his ability to stay away from tired cliches or predictable endings.
The only thing that really bothered me about this story was the way the people ascended to the "Greater World" leaving only their skins behind. I wondered why only their skins would be left behind, I didn't get the impression that they needed a physical body at all in the Greater World, so why wouldn't the whole thing be left behind? It seems that t was just the skin only for purposes of dramatic effect for the story, which I thought was a little lazy. But that was a fairly minor point, overall, it's a good story, with good characters that you could really feel for having to make tough decisions in an incomprehensible situation.
I will continue to look for more by Wilson, as he is becoming one of my favorite authors, and this book is definitely worth reading if you can find it.