I used piloted reamers in most pre-punched holes in all three airplanes I?ve built. No cracks, and the hole was cleaner and easier to deburr without taking too much material off. Never had a crack, holes were clean, results were good. If I wouldn?t have had these piloted reamers, I would have used a drill bit and not thought twice about it. I think some people get in to trouble when they over deburr the holes, hence the reamer requiring less aggressive deburing. I don?t think there?s anything wrong with either method.