I read cozy and historical mysteries, a bit of Paranormal/UF, and to mix it up, I read science and gardening books on occasion.
The danger of theme cozies is if you aren't that interested in the theme, the book suffers a bit in the reading. I'm not a fan of dancing - I don't dislike dancing, but I don't love it, so the theme of this book keeps me from getting lost in the story (plus, really, how much long-term murder and mayhem can you wring out of a ballroom dancing theme??).
It's a good book and I'd recommend it to any cozy mystery lover who would find ballroom dancing an interesting theme. The mystery is good; lots and lots of suspects with opportunity. I felt the ending was a nice departure from the cliche endings in so many cozies. Very likeable characters with just a soupçon of romantic tension. Great setting in Old Town Alexandria. If the theme had been something I found more interesting, I would have given this 4 stars. Still, I might read the third book when it comes out.