As I read them so close together, it was impossible not to compare this book to Lady of Devices. And in my opinion, A Study in Silks is definitely the better book.
The characters have more depth, the world building is better, and there is Sherlock Holmes. In fact I would have liked more Sherlock Holmes. Though I'm surely not the only person who kept seeing Benedict Cumberbatch and Martin Freeman whenever Holmes and Watson made an appearance.