i've owned at least 12 ulysses' thru the years and played around with many different "taller than stock" windscreens....some as large as riot shields....some slightly taller than the XT stocker. the inherent problem with ulys/xt's is that from a frontal perspective they're aerodynamically very "dirty". bug eye lights with a screen...bucket....hand protectors...somewhat large signals...lollipop mirrors....all play into air management or lack thereof and helmet buffeting. what worked for me and others may not do the job for you. but for me the stock screen with the adjustable Laminar Lip nicely and easily accomplished what i was looking for which was minimal buffeting along with moisture protection during inclement riding. this was with stock seat, stock bars, no risers. i'm 6ft and 32" inseam. and i never have nor ever will look THRU a windscreen. always over the top of.
see link below. Leo owns LL and a great guy. his customer support unrivaled. spend $6 for the pack of 20 extra fasteners which increases adjustment range. IMO riot shields on a uly/XT not only look like effing hell but adversely affect handling including the dreaded and dangerous handlebar flutter along with high speed wobbles.
http://www.laminarlip.com/xbxu.php