You mentioned two very key words. velocity and savaging. Managing exhaust is just as important as the intake.
If you're running enough boost, I could imagine where open headers would be more beneficial. I'm curious why you're saying that with a roots blower 'you can just run open headers'. That sounds like old-school muscle car mentality where you don't worry about exhaust tuning, but overcome it with more boost. I thought roots was more of a lobe design compared to our screw design. Don't know some of the particulars beyond that and would be quite curious why.
