In common with many others, I like the Edge books but don't love them. They're not nearly as good as Andrews' Kate Daniels series and there is no doubt that this comparison colours my opinion. That said, the Edge books are easy reading, stand-alone stories and more straight-forward in their "romantic-adventure" nature. If you're looking for that type of book then Fates Edge does the job well; I liked the two main characters Audrey and Kaldar and whilst I would like to have seen the romantic elements play out earlier in the story, the chemistry worked for me. It was nice to see Jack and George again from earlier books, and their story in particular added a darker edge to the book which I liked. For me this is the best of the Edge books - primarily because it was a simpler, more coherent "romantic adventure" story without some of the more complex plots of the previous two.
Andrews' writes in a style which I enjoy and her characters are strong and fun without feeling contrived. You can read this as a stand-alone, but I suspect most readers will be long-time fans hooked in by the Kate Daniels series. Worth reading certainly but it's not something I'll be picking up again and again.