I own this. It is so delightfully well executed that I cannot help but be impressed. And yet it is somewhat appalling in that I cannot bring myself to read more than a few chapters.
Just as the settings and context of Jane Austen novels can be compelling, the settings and context of Pride Prejudice and Zombies can be simply unbearable.
It took me over a year to get through P&P but it's now a favourite that I've enjoyed in many other mediums (The Lizzie Bennett Diaries[1] being the highlight).
P&P&Z, on the other hand, I found heartily disappointing, and impossibly tiring to read. I ended up listening to the audiobook instead, which made it a bit more palatable. There were a few good sections, but overall I wasn't much of a fan. That said, the movie is far worse, doing away with the little that was good about the book.
Agree, it's hard to read through. But I don't regret buying it for it's own silliness.