Purchased Witopia in July 2010 for usage in China. Had some installation concerns, but Witopia Tech Svc helped me resolve in one (1) correspondence (email). Basically, I've been up, running and VERY satisfied with Witopia!
In the past, used two (2) different providers, once in 2007 and once in 2008 for the Olympic (in Beijing), but both times for ONLY one (1) month since service was poor and performance was terrible. And I paid more the Witopia's prices.
Yeah, does affect speed, but impact is minimal and I am willing to trade couple of KBSs for youtube, facebook, etc. Now the family has youtube, facebook, and hulu - all the enjoyments of the my kids generation. In fact, we got it loaded on both our laptops and desktops (yes, only one cpu can use at a time). So we're now considering additional services (maybe CB).
If you're considering VPN from China, I would seriously consider Witopia. I am (we are) very satisfied with the performance, cust svc and tech support. In fact, I've already recommended the service to three (3) other expat families.