I have a pair of Pearl Izumi bibs that I'm pretty sure are knockoff Chinese-- they have less stitching and that stitching is irregular in places. Thing is, they're holding up every bit as well as my bibs with more/better stitching. And they fit, so... <shrug>

I also have two Castelli jerseys that are radically different in both sizing and construction. Both are large, but one is a snug race fit and the other one is almost baggy. But they both fit, and seem to be holding up equally well.