To be honest, I'm not sure how to rate this book. It is a collection of short stories by four different authors, and I think each story is an introduction to another collection by the same author. Two 5 stars plus two 1 stars averages out to 3. It brings two authors down, and builds two up, but I'm not sure what else to do.
I loved two, and couldn't finish two. One I couldn't finish, I did jump to the end to read the last couple of pages, and was glad I hadn't spent my time on it.
I enjoyed the worlds of the two I loved, although I thought Ms. Briggs's was by far the best developed.
I'm not sure these are true short stories. At the average length, I'd call them novellas. All I can say is, caveat emptor.