Tressel still has a lot to learn about being a coach at Ohio State versus the strangle hold he had in his time with Youngstown State. At YSU he could do what he wanted and no one cared, he had four I-AA NCs (Out of 6 NC Appearances, and 10 playoff appearances) to shut them up with. At OSU he has one and two failures, unacceptable.
Here's where Tressel makes mistakes, he relies too much on defense and throttles his offense, if he wants to win. And not just against the Big Ten he's gotta learn to let it go, yeah it's a Pete Carrol/Bob Stoops move but it's working for them. Tressel often does make dumb decisions but his record you can't deny. 208-73-2, the guy knows how to win.
OSU's defense was tops for two years in a row. Two years they held that top spot. This season there were too many variable moves to consider it for a third running, from a realistic stand-point. To say that the defense is overrated? Yeah by the media/National standards they are overrated this year, my personal belief being that I knew they weren't going to be as good, but they're not terrible either.