I don't exercise the Dremel very much anymore, but for polishing and contouring work like feed ramps on repeating arms and whatnot, Cratex abrasive-impregnated rubber rotary bits are the bee's knees. Diamond cutoff wheels are also great for cutting molded plastics. But in the grand scheme, I'm still a files and emery cloth kind of guy for a lot of the work that a Dremel can be used for. It's just got a narrow niche in my opinion.