Air or electric? You're asking mainly about an orbital disc sander. Where they become a "problem" is the operator. Moving too fast, using the edge, or letting it run in one spot too long are all "sins" of using this tool. Another is letting it spool up and then touching it to the surface.
Some tips to remember...keep it as flat as possible. Avoid the temptation of running it on the highest speed if it's an air sander since most different grits have an optimum speed. Don't "edge out" chips and scratches, work a large flat area around them instead. As an example, the average 1/8 paint chip or stone chip should feather out to at least 6-8 inches or be filled with repair putty before sanding. The whole idea is to keep a smooth level surface. ANY imperfections will be magnified in the top-coat. Keep it flat, use smooth fluid movements, and you'll be just fine.
