I guess it all depends on your definition of "benchmark."

My working definition of a benchmark ball is a ball that will allow me to get a quick and accurate read of the lane condition.  That is, if the benchmark is the right ball for the condition, I'd know it immediately, and if it isn't the right ball, then I'd know which way to go in the bag based upon the reaction that the benchmark is giving me.

If, for a particular bowler, the Raging meets these criteria, then a benchmark ball it is, at least for that bowler.
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...formerly "The Curse of Dusty," and "Poöter Boöf" before that...