Hi Kafka.esq (great handle, by the way)
Itís actually not like that at all, at least in our tests. With screens, like with many things, thereís more to life than sizeÖ
People vary in their experience of screens, so Iím not normally one to make claims for ours - YMMV etc. However, I find the Manta does make a big difference to the comfortable cruising speed on the Storm. I was doing a constant 85-90mph in relative comfort - not really possible on the standard bike.
It works like the screen on a sports bike (and of course theyíre generally very small) by smoothing out the airflow, reducing turbulence. Air pressure alone you can cope with - itís turbulence that causes discomfort.
Anyway as I say, itís a personal thing, but in my opinion itís one of our most effective screens in performance terms.