We often cut dirty wood (riverbank management) and RM chains work fine. As for the gauge debate, .063 is what everybody uses on stihl saws around here (SE France) but I couldn't really argue about technical advantages. We also have a few huskys using .058 chains. No issues with oiling. All I know is that both work fine and that .063 is the most available for stihl saws around here so we stick to it.