I had PGT's put in a few years ago. (Still have shutters too) I'm a Firefighter and have seen some huge dudes beat on them with a Pick headed Axe, and not even dent them.
(We do have saws that can cut through them) They are excellent windows, not only for storms, but well insulated, and you don't have to worry about punks trying to break a window to get into your house..