Nate had more than a few fails in big moments. But he wasn't a guy that you would say "go out and make something happen to win the game".
I do think he was the perfect qb for Kirk. A big qb who follows orders. Nate was never an all B1G qb, but he was above the average of the typical game manager qb. Not a favorite of mine, but certainly a solid above average B1G qb.
Personally for me, though, he's in the tier below the best qbs of the Kirk era. Banks, Tate, Stanzi, Beathard. The thing they all had, that I suspect Kirk hates, is that they would go off script and make a play. They are also the guys who were the most fun to watch. I think it's great when you can't predict with virtual certainty what the qb is going to do.