I think what you saw last year was a young, inexperienced, average offensive line, excluding the great Tyler Linderbaum.
Iowa wins with a very conservative offense that commits very few penalties or turnovers; a great, aggressive, consistent defense that consistently FORCES turnovers; and exceptionally good special teams that change field position. I do not see the Ferentz formula changing very much. He wants to run the ball first, which is dependent on the quality of our offensive line. I believe our OL will improve this year, which in turn will open up our passing game a little bit with some great TEs and improving WRs. I have never believed that the QB is a game changer under the Ferentz system (maybe Banks, Tate and Beathard were a bit of an exception). Maybe Labas could give you more of a run threat, but I'm not even sure about that. I think Petras will be your starter at the beginning of the season. It will be his job to lose. That is the Ferentz way.
Nebraska had one of the best offenses in college football last year, but went 3-9 because of turnovers, penalties and abysmal special teams, including unreliable field goal kicking. Iowa's kicking game, in contrast, has been terrific.
Iowa will contend for a good bowl game again this year, as well as a Division Title., with a much more difficult schedule than last year.
I'm not saying anything you don't already know, but to think it is going to change going forward is like chasing the unicorn. You aren't ever going to see it.
My feeling each year with Ferentz is that the defense is a constant, and so are special teams. We go as far as our run blocking can take us. Perhaps the OL really comes together this year, if it escapes the injury bug.