It is my personal opinion that a short story needs to grab you within the first two paragraphs. There were some in this collection of horror stories, written by a lot of authors that I was unfamiliar with, that did just that. But most of those were written by authors that I have familiarity with: Stephen King, Joe Hill, Dan Chaon, Neil Gaiman, to name some. There were some new to me authors that wrote well and I will seek their other works, but some just did not make too much horrific sense to me.
There was one particular story at the end of the book that I found extremely well-written; Insect Dreams by Rosalind Palermo Stevenson. The writing was definitely first-class and the story kept you compelled, although why it should be labeled a horror story is beyond me.
The book is definitely worth picking up, although there are probably stories that people will want to skip over.