I have been using this OJ for only an year and a half. Although, I use it intensely only during my college vacations, I feel the same way. As I use it only to prepare for ICPC, the cheaters going up in ranking doesn't affect me that much. What affects me is the number of submissions for a problem. There are lot of copied submissions for a problem, which makes it look easy, but it is not. I feel the problem setters should feel a little responsible for the solutions to their problems and report submissions that are copied!