I really don't think that the quality or reliability of any product has as much to do with where its made as how it was designed and engineered and what materials were used to fabricate it. I also do not personally believe that the "best" motorized bike can necessarily be built from a kit. I think what really matters is what you're looking for in a motorized bike, and if one kit or another can provide you with that, then I suppose you'd consider that the "best" for you, while another person might dsagree. Personally, I used the china 2 stroke kits for 3 years before upgrading to a fully custom bike (except for the frame) with a 98cc minibike engine, and this bike is fulfilling everything I want in a motorbike, but never got from the kits. But that's just my personal experience. Some people are very happy with the kits. It all just depends on exactly what you're looking for in a bike.