They were horrid last year on D. How much of that was athleticism, scheme, or simply giving up down the stretch after some losses? I don't know.
But we know that they aren't all-world, even with a new coach, attitude and some new players. They will still have their issues. Nebraska lost some salty receivers and a senior QB who played with a lot of guts last season. But the replacements seem to fit the offensive design better. Honestly, I'd expect Nebraska to score more points this year than last year.
The question comes back to whether our defense can slow down the ducks.