Yeah. Well not extended though. As a part of an overpriced study abroad experiance a few years back, they were hired and took us around. The guides were knowledgeable, flexible and spoke English wel (some were western educated).

Now for work, when we visit certain parts of the country (ie. when one of the investment funds is taking us around) Wild China handles their logistics and quite well I have to say. However, the warning is that Wild China is by no means cheap and I would not engage them for touring around Beijing or something like that where one can get lots of information and advice on the internet and on this board unless you are taking around a very big client, or something like that and have tons of money to blow and want piece of mind (ie. staying in Ritzes, hiring a Benz everywhere and you not worrying about anything). However, their multi-city tours might be interesting...

Furthermore, some of their more exotic tours look very interesting but once again, pretty darned expensive.

In short, my experience with them has been good, but I will leave it to someone far more informed to hopefully provide a more comprehensive view.

Edited to add: I think joining a tour group going to Beijing is a fantastic idea, if (and I think Moondog has said this a number of times), one is willing to milk the airfare and the effectively free hotel room, but then ventuer out on their own, from information gleaned here or from other parts of the web. We're more than happy to help!