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. I can do whatever you like down to .25 micron, but there is very little gain past 10 and is generally not worth it. Match or beat the accuracy of an EdGi for less money than a Prommy 0-200mm brass 25 200-500mm brass 30 0-300 Stainless 30 301-500 Stainless 40