There are several kinds of anthology in this field. One of them is the, "Hey, this genre and the authors in it have novel series that are selling like hotcakes! Let's do that, then!" kind. And that's where this book falls.
Seriously, constructing short stories and constructing novels is not the same skill set. Incluing readers on a situation if they don't already know the ongoing characters--and doing it without dragging a short story out of shape--is even harder. I would love to say that these authors, by and large, managed to do that very well, but honestly, they didn't. P.N. Elrod and Jenna Black at least managed to write readable short stories in the context of their ongoing heroines, but even those were not, to my way of thinking, outstanding examples of the short story form.
If you have favorite ongoing paranormal romance series, and you want to be completist about reading them, it may be worthwhile for you to check out the table of contents on this book. If you don't follow any of these authors in their ongoing series, I can't think this anthology will be of much interest to you. If you're interested in paranormal romance and want to see who does it well, I have every hope that these successful novelists do it better at novel length.