Such a bad way to describe an item as seeminly bad, but actually having a "mysterious" hidden power upgrade... Everyone who can do math, can calcualate the DPS increase. Even at non upgrade level its super good, unless other items usually give 26% DPS increase or more, then its another story, but besides weapons I dontknow of any game, who does this. At least it could have a been a hidden "yet to know" effect like the legendary cloak from WoW Pandaria, that only Mr Second knows about, because he already played all the Addons.
But in this case its just obvious, that the ring is good... Must be because math and reasons. -.- Because we all know you have to study in university to know about simple statistics. ^^