A unique, well-written alternative on "Pride & Prejudice." Be warned that little of Austen's original plot remains... however, in a way isn't that why we read other takes on her work, to see how the characters would react to a change in circumstances?
Johnson's take on the characters is certainly enjoyable and the romances delightful. Elizabeth and Darcy are not the main couple in my opinion, but I personally have no objections as following Mary Bennet's story is delightful.
All-in-all I would say that this is one of my favorite "P&P" related books. It must be, I've read it twice well within a year!