I'll keep it short and sweet - am I better served picking up a set of undersized plywood bits (7/32", 11/32", 15/32" and 23/32") or the equivalent metric offerings (6mm, 8mm, 12mm, 18mm)? Just doing the math seems that the metric ones are closest to the actual dimension. Please advise me. I don't want to get into a brand debate, just advice on proper sizes.