SCT versus random orbital sander?

DA and random orbital are 2 different sanders. Dual action is a forced pattern used for knockdown of rougher material and removing paint. The guys would call them "Mud hogs". Random orbital is a finish sander and some can be purchased with a tighter pattern for fine work. A lot of the old guys remove paint with a high speed grinder. you have to keep it moving though. 36 grit can tear stuff up pretty easy.