Six Wakes is a science fiction version of a locked room mystery, and Lafferty did a good job at keeping me guessing for most of the book. The gradual unravelling of the mystery is handled competently, although the final revelations seemed a little bit convoluted and unlikely to me personally. The characters are interesting and there is plenty of atmosphere. 

I do like it when science fiction books have conversations about ethics and morality, and I enjoyed the various discussions here about the repercussions of cloning as well as ethical issues concerning manipulation of DNA.  One slight criticism is that I would have preferred more focus on the ethics of cloning itself - is it right that a person's consciousness should be essentially downloaded into a clone's body? Is the clone essentially a person who is having their body hijacked, or are they not a person until the "mindmap" is downloaded? This question isn't asked or answered in the book and it left me mildly uncomfortable. 

Overall I liked, rather than loved, this book. I do recommend it, I think it's a decent mystery thriller, it just isn't one I am likely to ever reread.