Speaking from riding experience for the bikes listed below, the best bikes out there as far as wind management is concerned is:
thanks for the illustration of different priorities.
I prefer nó shield whatsoever.
But then I prefer travelling over twisties.
My style cruising is continental european; defined by the leísure, not by US style lang distance straight(ish) roads.
The R18 seat is very much suited to the former, less armchair for the latter.
Also positivelly lóath sound systems on a motorbike btw.
The windjammer cruisers, whether HD, BMW or GoldWing are for mé defeating the purpose, route around the essence of a motorbike. I have an MR2 Spyder instead. Took the sound system out. Again has no place in the wind imo.
Back to wind protection I wager you have not ridden the wind tunnel designed Moto Guzzi 1000SP or R100*. Both absolutely perfect but best at 120 km/h plus, like grand touring at 100 mph all day. Distance gobblers from days long since past. Drive like that nów and your drivers license is gone same day. So I am adpating to speed limits et all, no need for wind proteccion and I will happily eat the insects too. A low price to pay for the unobstructed experience.
As to the subject imo BMW shot themselves in both feet with the launch.
A launch is like any first impression and they totally, completely went heritage image. Look at their homage and then concept bikes. They hit all that spot on and the bike ís a wonderful modern retro. They executed áll aspects to perfection in top notch quality.
It completely missed the (US) HD cruiser market though. Those could not care less about pre-WW2 Bayerische Motor Werke. If at all then negatively.
Néxt they díd come out with proper cruisers on par with HD/Indian albeit with better quality.
* I suggest áll here who have never seen one in the metal totry have a close look. For me it is BMW´s motorbike high water mark and in terms of design, material and build quality a high water mark for the entire post war motorbike industry. And I am serious; do have look if you can.