I am just a hobby builder/painter, so I can be more picky than people who are buying to repaint and sell. Problems with knock off plastic blanks, for me, have included leaks at hook hangers, cracked bills, and blanks that were supposed to float that sank. I think the quality control for commercial baits is better, so there is a much better chance their baits will work, right of the package. Some plastic blank suppliers have better quality control, some worse. So it's more of a crap shot if you buy from a supplier who doesn't have good quality control, and some have a higher percentage of blanks with problems. You won't get that with commercial baits. Their blanks are pretty close to 100% good.