I have a 'PowerBronze' screen, imported from U.K. I think it was about $165 delivered. High strength & super clear, it seemed better than the others I had seen. It is about half as high again as the standard one, a little bit wider and slightly dished to throw the air up over the helmet.
I rode the same bit of highway on the same day with both screens and there is a definate advantage with the new one; I pretty much have a 'dead air' zone from shoulder to shoulder and up to the top of the visor. I've seen bugs happily buzzing around behind the screen while I'm at speed on the highway... Plus I liked that my vision is still well over the top of the screen, not through it.
Do you ever come down south riding John?