However, with the quick detach options you can have it both ways. I'm still considering getting one. Maybe a low profile smoked one would be cool on my scoot.
In my opinion, removable/detachable is the only way to go. I personally don't think a windshield enhances the appearance at all - in fact I don't care for the looks at all. They sure do help cut the wind, and also keep the bugs/sand/rocks/grime off you when riding at speed. Just be sure you get one that is the right size... don't get the shorty just because of appearance, as there is little asthetic difference between the shorty and standard (and even the tall for that matter - the look sucks either way) but it makes a huge difference in its effectiveness.
Just put a windvest on my fxstc and it's pretty good. I'd say it takes about half the wind pressure out. Just enough to be comfortable at higher speeds but still gives enough wind for motorcycle effect. It's actually plexiglass and not lexan. Plexi never dulls and more scratch resistant than lexan. Plexi will however shatter if hit hard enough or crack at the holes if flexed too much. That's why it's so thick, to make it more durable. Having the custom , I was hesitant to go with a larger windshield and eventually lowers. Just too big for my tastes. Windvest did not detract from the bikes beauty. Actually looks cool. At 5'8 I went with the 14x14 and ran it full up on the holes and brackets which puts wind blast about 2" above my helmet.
Ron
Plexiglas is acrylic and will yellow and get brittle over time. Between that and the fact that it will shatter if hit hard will steer me towards a polycarbonate (Lexan) windshield every time.