Improves accuracy noticeably every time, saves money on expensive brands I use diamond based compound with metal and plastic lapping inserts for the fastest and best finish EdGi uses 7 micron paste, PDI uses 20, and I can go down to .50 micron, but there is little gain past 10 and is generally not worth it. You can match or beat the accuracy of an EdGi for less than a Prommy 0-200mm brass 25 200-500mm brass 30 0-200 Stainless 30 200-500 Stainless 40