I found this Lonely Planet very disappointing, compared to other lonely planets that I liked very much.
The Yucatan Version is very negative; if you read only this, you think there ist danger in every corner and would prefer not to go there at all. Well, I went anyway, and it was a great holiday!
But I met other tourists with lonely planets (Yucatan or Mexico) and most of them said the same. If you go east, lonely planet is the best, but not for Mexico.