FYI - I measured how much the bike raises and lowers the shield, and removed exactly that much from my OEM shield. Thus, in the highest position, it is the same height as an uncut shield in the lowest position. But you get more air under it. I didn't want to trim more than that.
I'm 5'9" and it works pretty good for me. In lowest position the cut shield dumps air right on my hot crotch. Wait. That sounded funny.
Barry