Like many people, I read the mixed reviews for prior editions to this guide, but didn't see a better alternative, so got it, hoping that the kinks had been worked out. They hadn't.
No travel guide to the largest and fastest-changing country in the world can get everything right, but this guide gets a lot more wrong than it has any excuse to. I first encountered this in Macau, when, after wasting a fair bit of time following its maps, I was assured that the official "Tourist Map" had full bus information. It in fact has no bus information, which was not a pleasant thing to learn at night, far from my Hong Kong hotel room. But things only got worse from there.
One problem is that the hours posted in Lonely Planet are very often wrong, but, even more so, misleading. Thus, when the guide indicates that the Forbidden City closes at 5:00, what it doesn't tell you is that the officials close all buildings and start kicking you out at 4:30, which can be a huge disappointment if you waited to see a particular exhibition that has closed. Contrast this with the Old Summer Palace, where no one cares if you stay well after closing, making it the perfect cap to a late afternoon. These two places also illustrate a huge problem with the maps in the book: They don't tell you where the entrances and exits are. Thus, you could walk an extra mile than you need to get to the only listed entrance in the Old Summer Palace, and another extra mile to get to the ruins therein. Or, you could waste lots of time in the Forbidden City because Lonely Planet doesn't deem it important to distinguish doors from walls.
Costs and cost structures are often far off or ill-explained, and I checked with locals who insisted this wasn't because of any recent changes. There are no subway maps, which is especially bad in Beijing, which is famously stingy with having such maps. Scam warnings are far, far too specific; scams warned about for Beijing also take place in Shanghai, so if you go to the latter first, you'll be unprepared. The best warning would be that anyone from anywhere China approaching you in a tourist locale speaking English wants to shake you down, not to practice their English, so be careful if you follow them anywhere, even somewhere official-looking. Sad but true. And the pages of Chinese words in the mini-phrasebook somehow neglect food-related ones like "hot," "cold," "water," or "rice." These basics would be especially useful when being served a spicy, salty meal with warm water in the midst of the summer heat.
It's also clear that this book hasn't really been updated, even on the most important things. One tell-tale sign is talking about "targets" for 2008 rather than actual statistics. A more worrying sign is the lack of knowledge of the fact that the east side of the Bund, the main Shanghai tourist site, is closed due to construction for Expo 2010. This is not a brief closure, but a huge project that will likely take about a year. The biggest tourist site in the biggest city of the country and Lonely Planet makes no mention of this? Sadly, that's what I came to expect of Lonely Planet China. I can't give it fewer stars, because I don't have a better alternative and at least there is some Chinese (albeit inconsistently) on the maps and site lists. But I'd certainly wouldn't recommend it.