I have the cheap china adapter, and it has been working perfect for the month or so that I've had it. It was a little laggy with torque lite, but since I've upgraded to pro, its been awesome.. I guess I just got lucky haha.
i have the cheap adapter too. works fine a connects, but its slow. i didnt buy it for the performance stuff though more for a tool reading live data from the sensors, it does that fine. if you want it for the performance measurements definitely dont get the cheap one.