If I were to choose the S&B closed box style I'd run the lid on, side plug off, and no extra foam filter. If you really look over the flow path to the air intake it's pretty sad. Very little direct flow requiring more pull from the turbo versus a open air style.
Biggest thing for me was the CAC controlling the air temp to the intake manifold. It makes ZERO sense to think there's any real world CAI system for the 6.7L, it's just not possible to avoid the secondary coolant system from "heating" the CAC airflow.
Not to mention when it's 100*F+ outside, what's making the air "cooler" going into the filter.....nothing. So whatever performance arguments anyone wants to make is ignorant about the real world conditions.
As an different but my most recent example : I was out to buy a new lawnmower. At the big name direct dealer in my are looking at a Toro, I mentioned to the "salesman" I noticed there was a hose connection to wash the under deck area. He starts into some smart-a$$ comments about engineers, design...blah blah blah..."You know water and metal don't work and it's going to cause you more problems down the road." Not missing a beat....me: "Really ....cause grass has water inside it, cause it needs water to grow, hence there's plenty of water getting around the under deck area. Right??". He shut up, ended his contact with me, "needed to answer the phone."
So ....just think it through. Run what you want. Mines been just fine, no "performance" losses anywhere.