Another issue in deciding if a certain plane should be perked is its "sporting chance" factor.
We inhabit an arena where most people have no problem turning a 3 on 1 into a 4 or 10 on 1. Since the community isn't charitable enough to give a guy a sporting chance, he ought to at least have a few free plane options that will give himself one, like the La-7 and Spit XVI.
People always talk about how many windows, monitors, joysticks, and cats have met their end because of these planes. Few stop to think about how many were saved because of them.