Most of the time when we're home, I don't really worry too much if the kids are in long pants when they should be in short and vice versa.  But when we're camping and we leave for the day to go hiking or even into a local town, it can really make for an unpleasant day.  These really fill the bill in that regard.  The zippers work great (zippers are a real pet peeve of mine) and since they are essentially two pair of pants in one, they mean fewer pairs packed.  They are extremely light-weight and the kids say they are comfortable.  Can't wait to try them out on our big trip to Alaska this summer!