It's a very informative guide, especially for people who have never been to China before. All the information about Visas and crossing to Shenzhen from Hong Kong is very valuable. The point to talk pages are very smart too, although I skipped most of them as they're printed landscape and I was reading the book on a tablet. That said, I think this guide is more useful if printed.
About the market itself, I've been many times to Hua Qiang Bei (by the time of writing this I'm living in Shenzhen), and truth to be told I found it a bit disappointing. At least I could see in this guide that there's more to it than what I've seem so far. I'm looking forward to going back to HQB with this guide under my arm.