I was at the 5th Avenue Apple Store today getting a new iPad for my mom and while looking at some iPad minis, the salesman looked through countless dead floor models to find me a working one. He said they have been having numerous problems with lightning cables breaking as a result of customers aggressively using them, therefore causing the floor models to not charge and their batteries to drain. I haven't had any problems with my lightning cable so far, but I am concerned that the smaller size makes them less robust. Has anyone had problems yet?