Yeh it is supprisingly good .I to with quite a few others had my doubts how well it would perform ,But I have sharpened 3 sets of drills various other hss bits and ground all sorts of things with it but the disc barely wears and it leaves a reasonable finish .the main reason I did it was I was sick of glueing new pads onto the old dick that Watson there it's a pain at times ,Here are some drills I sharpened with itThe use of the angle grinder wheel is a different spin to me, is the performance good ??