It’s difficult to know the strength of polycarbonate shells, and it’s difficult to test them. We can assess the flexibility, relative weight, and composition of the material, and take into account the brand’s reputation, but that’s only enough to give us a rough idea of the limits of these suitcases. Our primary goal here, however, wasn’t to find the strongest luggage. Instead, we wanted to figure out which bag was the best to pack and the best to travel with, and which was ultimately worth the price.