First off you should know that even though the word witch is in the title vampires feature prominently in the book as well. I usually avoid vampires, but since I never read anything sensible like a book flap, I didn’t know they were in here until it was too late. Fortunatly gruesome incidents were minimal and I ended up enjoying the book.
Would I recommend it? Well now, if you are someone like John who’s sense of the universe is completely disrupted by vampires who don’t die in the sunlight then you’d better avoid it. If the specific traits and habits of vampires are of less importance to you this may be an enjoyable read with an interesting mix of magic, history and science.