See my post under "Holy Buffetting Batwing", where I asked the same about my '07 SERK. Having the wind off the chest makes things better, but the eyeball rattling vibration from air coming up alongside the tank didn't. I'm going to try a Vanillazilla batwing (uses the stock mounting points and weighs seven pounds so can be removed as quickly as the clear plastic ones) and see what it does. I don't care about having speakers, I just want the wind protection.
This is exactly the issue I have with windshields and fairings. They make buffeting... you can 'adjust' the buffeting to be over your head or someplace less irritating, but it'll be there... and you can either feel it or hear it.
As far as aerodynamics go, how you cut the wind is important, but equally important is how you 'put the air back' behind the bike. A huge turbulent 'wake' behind the bike causes lots of drag. Shields/fairings slow the bike down (like pushing your bathroom door through the air) and create issues with handling too, especially if they are mounted on the forks. Not to mention the added weight...
These days, some bikes have bodywork designed in a wind tunnel to be more efficient thru the air, like the new BMWs, the 'Wings, and the Victory Vision. Sometimes form follows function and what works best probably won't be cool-lookin'.
I'll take the naked bike and the wind.