Because they are attached to the downtubes they do catc
h the wind, you feel it in the handlebars. That was my impression.
They look just like the ones I have on my Heritage. I know they don't look like much but I like mine a lot. I get very little wind on my lower legs and in this weather they really keep the cold air off my legs. Between my windshield and the deflectors I stay rather comfy.
Take a look at this thread, Eleft36's post #2 has a picture...
http://www.hdtimeline.com/touring_models/12345-air_deflector.html#post105063