We recently travelled through China and this book was worth its weight in gold! We rarely went anywhere without it and I can remember many a long train journey pouring over it for ideas and inspiration.
It was particularly helpful in the early planning stages of our trip when we were at home in cold England and trying to imagine the countries that we were going to visit. It assisted us in planning our route and discovering the places that would be of most interest to us.
Of course, when you are actually there and living the experience, you make your own way and your own decisions, but this book was a bit like a security blanket for us - whenever we lost our way or became confused, it was always there to help. Due to any travel book being out of date almost the minute that it's published, of course a few recommended restaurants/hotels no longer existed but we used websites to help us with those things anyway. What was most valuable, was the history and advice about each different country and the things to do/attractions there - most of which we wouldn't have even known about before reading this book.
Lonely Planet is always brilliant, they are my preferred travel guide and I use them every time I travel. I love that the books are really down to earth and offer real advice that doesn't beat around the bush - if a town is run-down and seedy they will tell it like it is!
Before I went to China, I had heard rumours that the Lonely Planet books were banned from the country and that they would be taken away from you if you attempted to cross the boarders with them. That did not happen to us, but I would do your research before travelling there just in case.
If you are planning a trip to China - buy this book! Even if you don't take it with you (it is quite heavy) it will inspire and excite you before your travels. Another piece of advice: if you are planning on travelling light, rip out the pages of the book that you will need e.g. the provinces that you are going to, and take them with you as smaller, lightweight books rather than carrying the whole thing about with you. I'm not ususally one for defacing books, but as any fellow traveler will know, you have to do what you can when you're on the road!