SAENG Winglet
I paid a visit to SAENG this week - they are located about 90 miles from where I live. Got to talk with Charles Saunders, the President of SAENG TA for about an hour about motorcycle wind management.
He said that if you put your hand parallel to the top of your screen when riding (put it in front of your helmet), and that gives enough improvement,
then the Winglet will probably do the job for you. If you need more, then the Wing-tip is the way to go. The SAENG Stealth Edging is for fine tuning if you have a shield that is very close to doing the job but you need an additional inch or so of lift. I put some stealth edging on the tall aftermarket screen I have on my V-Strom and I'm all set with that machine. I gave the Givi on my Burgman 650 the "hand test" and it would appear that the Winglet will do the trick, so I've ordered one.
The SAENG stuff is pricey, but it is nicely crafted, and both the Winglet and Wing-tip devices are tuneable - you can adjust their tilt in relation to the Windscreen. This can make a big difference in getting the proper venturi effect working. The less expensive Laminar Lip, which is their primary competition is fixed - not tuneable. The SAENG devices also mount on top of the screen - the Laminar Lip glues onto the front of the screen, extending just slightly beyond the top of the existing screen.
Spending $75 for the Laminar Lip vs $122 for the SAENG Winglet was tempting, but I think the Winglet will do the better job for me. We'll see.
It is also possible that the larger Wing-Tip would have worked for me on the stock 650 windscreen. But I had already purchased the Givi, and the wider Givi takes the wind off of my hands, arms & shoulders - a nice thing as the colder temperatures settle in.