Overall, Ertz was a serviceable QB this year. Really, I think the only loss you can pin on him is WVU -- and that's because he couldn't make a lot of the throws the OCs (for some reason) were calling.
He improved a ton over the course of the year, and I have high hopes for his future. He essentially had Klein's junior year as a sophomore. Imagine a third year with Klein! Hope Jesse doesn't become crippled by then.
Side note: in two different games this year, the commentators referred to him by "Zack." What's up there? Some nickname? MIR?