I tell you one thing they are good for: having me chase dimensions that mean nothing to what is actually the problem. I cant tell you how many times dimensions are out on a new part and they have me checking dimensions that have nothing to do with what is actually out. We do plastic injection molding and the engineer asked me to measure flatness on an older part so he knew what we could hold (for a tolerance) on the new part. I was dumbfounded, they are two different parts, two different molds, two different materials. How could the flatness of one part predict what another part could be? Its plastic, fool.