Pros: Good overview, decent background
Cons: More focus on Hunan differences would be nice
I bought this after liking Dunlop's first book, Land of Plenty.
This book follows much the same format. I'm not sure you strictly need both books if you're mainly looking for an intro to Chinese cooking, but if you want to go a little deeper into regional cusine and like her style, they make great companion books.
Personally, I do think a little more writing about what differentiates Hunanese cuisine would be nice. She does talk about it some, though, and sometimes I think I'm obsessed with details, so don't let that objection stop you from buying it.