I read this series when it was originally released. I wasnt happy with where the series eventually ended up late in the series, but the earlier works are fond favorites.
People buying this book (or others in the series) because they are fans of GRRMartins Song of Ice and Fire series are likely to be disapointed due to misaligned expectations.
The only thing this series has in common with the Song of Ice and Fire is a gritty certainty that favorite characters will get killed....or worse, and the use of widely scattered often disconnected characters and plotlines that sometimes may cross but also might never. Further, as this is a 'mosaic' novel, GRRMartin isnt the sole proprietor of the stories.
Treated as a seperate entity from GRRMartin's more recent series, the Wild Cards series is a fairly unique and often brilliant body of work. Due to its nature, not all of the short stories will appeal to everyone; to be sure there are stories and story arcs that dont appeal to me either.
Regardless, taken as a whole the series is really something special. Its similar to a massive wall mural which cant be appreciated from up close; you have to pull back abit and look at it in its entirety to fully appreciate the overall effect.
The strength of the series lays in its deft characterizations. Some of my favorite fictional characters are from this series; the Turtle, Croyd Crenson (the Sleeper), Golden Boy, Mackie Messer, Carnifex, Mr Nobody, Jumpin Jack Flash (et al), Kid Dinosaur.....the list goes on and on.
The series really picks up in the second book, but the 1st is where all of the necessary background resides.
Unfortunately, the books are being released in a grossly overpriced large softbound edition; my advice it to find the original paperbacks in a used book store.