First off, for full disclosure, I am no Viking fan. I am a Packer Fan. I have even been described as a Packer troll, though I conduct myself politely, do not offer excessive opions, and rarely am anything but proper and polite, even when I disagree.
As for Cousins, I am just going with an eyeball test, not arguing stats. My recollection is that he has big games, occasionally, but that he finds ways to disappear in important contests. He is good, he puts up stats. Even impressive stats, but he doesn't tilt the field, he doesn't dominate games. He is just another competent Q.B. The Vikes had that with Bridgewater, then Bradford, and then Keenum. Is he a bit better, maybe. Is he Brady, Brees, Rodgers, Wentz, Roethlisberger, Rivers, Newton, Stafford, Wilson, I don't think so.