I think there are many variables. Racquet, pattern, swing speed, etc. I'm guessing most of us don't play like Jack Sock. For me it comes down to experimentation and what works for ME. I was dying to try lower tensions but all my peers were in the mid 50s in various configurations. I went for it and found something I love now. My partner never tried a racquet strung below 50 and was shocked at how it felt. Sometimes you gotta just give things a try. Some of this is so individual.