The more important spec is string stiffness at a given tension, defined as the incremental amount of force needed to further stretch the string a little amount, usually measured in lbs/inch. In other words, stiffness determines the mechanical response of the string, not the tension, even though there is obvious correlation between tension and stiffness for a given string. Perhaps this is obvious to some people, but since I was a kid, I had always incorrectly referred to string tension as an absolute metric for comparison. I had stopped playing consistently around 2007 when I graduated from college and, when I returned to the sport 10+ years later, was shocked to discover that people were now stringing their racquets at tensions below 50 lbs. I used to string my racquets at 60-62 lbs. with synthetic gut and it was unthinkable that any decent player could keep their shots in the court with anything less than 55 lbs. At some point it dawned on me that because poly strings are inherently stiffer, in order for them to feel comparable to a nylon string or natural gut, you have to string at a much lower tension. This revelation that stiffness is the dominant metric also made me consider that perhaps "stiff" polys could be as comfortable as multifilament nylon, as long as the tension is low enough; that is, polys are only bad for your elbows if you allow them to be stiff by using a tension that's too high.