It works, but you have to be very advanced in electronics to use it correctly and benefit from everything it offers such as datalogging. I've seen success and failure with it.
I tried one of those out. I got most of the way through the project and bought an AEM wideband.
Unless you solder your own boards its a bunch of work and headaches and the price savings is very small. Read through the instructions carefully theres a lot of stuff not there unless your OK with ghetto. You need to buy parts to make your own connector harness for the O2 sensor, a case for the board, which is HUGE and ugly, theres a bunch of stuff. The AEM wideband even comes with an exhaust bung is compact, clean, water tight its a better all around product. My $.02