Being a huge Anglophile and a huge fan of GoFugYourself.com, I've been looking forward to this book since the girls announced it last year. There were a couple places where it looks like they got a little thesaurus-happy, and I didn't like some of the plot turns, but that had more to do with the narrative I had in my own head about this group. Overall I loved the writing style (very similar to GFY), and the fact that they included some inside jokes from their coverage of the real-life royals. And I REALLY loved their attention to detail when it came to history (whether real or when part of their invented family tree) and the houses / castles / palaces / etc. that served as the backdrop for the whole book, it gave everything a very authentic feeling. 
 Most of all, I loved how it drew me in and how I was, just, SO into it. It's been a long time since I was so connected to a book that I thought about the characters when I wasn't reading, and role-played how they could handle their current predicament, as if they were real people and I actually knew them and they might ask for my advice. It's a real testament to Jess & Heather's character development. (And, obviously, it doesn't hurt that it's semi-based on real people. I mean, there were times when I'd see a picture of Will & Kate, and my first thought would be, "Ugh, I can't believe he did that... Oh wait, they're not Nick & Bex...") 
 If you're not a "royal-watcher," you might have a harder time caring about the characters and the situation their in. But if you are, it seems like an incredibly real world that you've always wanted to inside look at. And it makes you wonder how much the girls got right ;-)