I generally stay far, far away from Jane Austen spin offs and fake sequels. I'd much rather re-read the original novels than read about the adventures of Elizabeth and Darcy's children or, worse yet, read a version where the characters are recast as vampires or warlocks or something.
The exceptions to this personal rule are two books by Shannon Hale, Austenland, which I read a few years back, and Midnight in Austenland, which I came across at the library and read over the weekend. Both novels are set in a modern-day British manor house that serves as a complete Austen immersion experience, where vacationing guests dress in period costumes and meet actors posing as Regency-era characters. Varying degrees of romance and mystery ensue when the feisty heroine of each book arrives for a stay.
From the reviews I've seen, there are a lot of fans and a lot of haters of these books. The latter group probably has some valid points mixed in with their complaints, but I've found myself thoroughly enjoying both novels. They're light and fun and the premise of a Jane Austen theme park is just tongue-in-cheek enough to make you feel like you and the author are in on the joke together, which goes a long way in negating the some of the cheesier, potentially cringe-inducing scenes.