If you're looking for a good, solid anthology of post-apocalyptic short stories, then this book is awesome. I've seen complaints that this book is too sci-fi or not sci-fi enough or that the stories aren't well fleshed out, and I think it's unfair. This is a collection of short stories, not a collection of novellas, and to be honest, I like that the stories don't tend to focus on what caused the end of the world; I want the reactions of the people and what happens to the lives in that world.
Most of these stories are very well written. Yes, some of them have a political bent, but I think that the post-apocalyptic sub-genre is inherently political since much of it involves societies, why they fall, how they react to extreme stress and how they form (or don't).
Like any anthology, this series has its highs and lows. I think that the stories in this book were largely good, off-setting any not-so-great stories.
My favorites were:
"The People of Sand and Slag" by Paolo Bacigalupi
"Dark, Dark Were the Tunnels" George R R Martin
"Judgment Passed" by Jerry Oltion
"Speech Sounds" by Octavia Butler
"The End of the World as we Know it" by Dale Bailey (My favorite, perfectly written)
I did not like three stories. Coincidentally, the first two stories ("The End of the Whole Mess" by Stephen King and "Salvage" by Orson Scott Card) were two of the three I did not enjoy, and when I started the book I was really disappointed, thinking that I had made a drastic error in picking up this book. Luckily other stories make up for the bad start quickly. The story I liked the least was one I was really looking forward to after reading the introduction, "Episode Seven..." by John Langan. It was written as a kind of "answer" to Bailey's story, but the style of narration and the stream of consciousness writing did not work for me and distracted greatly from the story.
My only real complaint was that I don't think "Mute," by Gene Wolfe, should have been included. I think the story is absolutely fantastic and loved it, but I don't feel it belongs in this anthology because it is not post-apocalyptic, but pure horror (about Death, not a post apocalyptic world in any way).