**BAD** is relative, the best scenario for your engine is a perfectly clean OEM paper filter. Because we live in the real world we are faced with different levels of BAD.
Any change to the intake systemshould be followed by an ECU reset, that would allow it to re-learn the new airflow patterns for a given filter, unfortunately the stock tune is only capable of learning to a certain point so an ECU reset wouldn't help if you built a completely open intake unit.
I am personally running an AEM drop in panel because my paper filter was muddy, I have been running it for about 5k miles and it seems to be holding up well. It is definitely not recommended by cobb for their stage 1 tune but the difference in airflow is negligible.
Slow is Smooth > Smooth is Fast