It's a worldwide problem of buying crap because it is cheap. If you can't buy something nice, don't. If you need it once or twice, rent it. It starts with older world values of paying for quality and making quality. BTW these resell well: good luck with the off brands.
IT depends on what your nailing and what size nail your using. In my opinion, do a test strip starting at 70psi and work your way to 90psi. When it drives the nail head to your satisfaction, there you go. I also know roofer regularly carry a hammer with them as if you nail into a knot or hard piece of wood, it is nice to pull out your hammer and knock the nail in the last bit rather than trying to reset your pressure or running to high of a pressure. hope this helps.
