To really answer that question, what kind of lane conditions are most commone for you to play on? What line are you looking at playing? Everyone's definition of "benchmark ball" is not the same. I have thrown both but find the Sure Fire to be my "benchmark ball" this does not mean it is the first ball out of my bag (that is a Grand Illuision), but it is the ball that I can throw on most any lane condition to get a read on how the lanes are playing. So are looking for the first ball out of the bag or a benchmark ball as I described.
Mark