Many members here are using the German Flex 3401, which is a forced-rotation DA, kind of a cross between a rotary and a DA. A bit more expensive and somewhat less flexible in pad selection, there are varying opinions on its utility but it definitely has more power than a PC (Porter Cable) and is easier to use than a rotary. There are a couple (maybe only one) other forced-rotation DA's but they don't seem to be as popular or available as the Flex.