Susanna Clarke's Jonathan Strange and Mr Norrell was a perfect melding of style and substance. It's impossible to imagine that story being successful in anything but her pastiche of 18th century prose. The Ladies of Grace Adieu is similar, in that Clarke has again written her stories in a pastiche of old writing, but these stories show her range within that format. These stories are by turns gothic, whimsical, or fairy-tale-like, and each one has its own narrative style that fits perfectly.
As a side-note, Clarke is now my go-to example for how to pastiche 18-19th century fiction. Jonathan Strange and David Mitchell's Cloud Atlas are the only examples I can think of where the writing doesn't end up setting my teeth on edge. (Mitchell, of course, is working in a very different genre in the 19th century sections)