So, as expected, Lucy Undying is fantastic, especially for people who know the original Dracula well.
Dracula, of course, is an epistolary novel. Which is to say, it's told through diaries, letters, a ship's log, newspaper articles, etc. And Lucy Undying, in addition to saying "wow, Bram Stoker and his characters were extremely sexist and gross toward Lucy Westernra" also asks the question "what if some of those first person narratives in Dracula were lies?"
What results is not only a feminist take on Dracula -- if Vampire: The Masquerade is vampirism as addiction/STDs, Lucy Undying is vampirism as rape culture -- but also a great nesting doll full of twists (don't skip ahead to see whose name is on each chapter, as you'll spoil the very fun surprises).
As always, I think vampire novelists are almost always highly influenced by vampire RPGs. Not only do we have memory loss as a key component of vampires (as in Thousand Year Old Vampire, where it's the dominant theme), but we also get an amazing twist on a blood cult (this book should probably be required reading for anyone who wants to pull off a non-cliched blood cult in their VtM/VtR game), references to "the Final Death" and other items that read very much like someone inhaled a whole lot of White Wolf or Onyx Path back in the day.
I am a tough audience for vampire fiction and I think this probably the most satisfying vampire novel I can remember reading since the original Dracula.