As a fan of all things Lovecrafty, a new anthology of Mythos short fiction curated by ST Joshi, the leading Lovecraftian scholar was very exciting.
As someone who doesn't really love short fiction, and has found a lot of the mythos short story collections wanting, I was a little ambivalent about trying yet another one.
The good news, overall, is that Black Wings of Cthulhu is good. It's not superlative by any means, but it's not a disaster like many of the other compilations I've read. It's good, and that's a good thing.
The problem with the book in a nutshell might be the use of the more cosmic aspects as well as the unseen madness. This is partly because of my preferences: my favorite stories in the book included ones where we could actually experience the horror first hand with the protagonists of the story (like in the tales involving the woman who bought meat, or the man who picked up the tentacled coin). The stories I enjoyed the least were much more abstract. This didn't mean that those stories were necessarily failures, but more that they may not have been as interesting as perhaps they could have been. This isn't to say that any of them come close to the eye-rolling tendencies some Mythos stories I've read have had (such as the "Cthulhu is in my computer modem" story I read some time ago), but too many of the stories in this collection ended about as softly as they began, with little to stick with.
Overall, the book is what it is. It's definitely worth picking up if you're a hardcore Mythos fan, because there's enough good (along with the stories up top, Laird Barron's story is predictably superlative, and there are at least 3 or 4 others that are quite solid) to go along with the not-so-good, and the stories are almost all short enough where you won't be making a major investment of time or energy if you dislike a handful.