Lower shields usually buffet LESS then the big ones.
If you're lucky, you'll end up with pure air on your helmet which is a lot more
comfortable then buffeting behind a (poorly designed) big windscreen.
Try riding your DT without a windscreen for a few miles and you'll see what
I mean. More pressure from the wind but a lot less noise (with a good helmet)
and head shake.
I was NOT happy with the stock windscreen for my 5'11" (180cm) height, it
was actually one of the worst stock screens I encountered on a scooter.
I'd probably get a smaller one AND a HUGE one for winter.