I have the KTM Hard Parts windscreen from KTMTwins, shown above. It's a noticable improvment from the factory setup by taking some pressure off my chest at highway speeds. Helmet is in clear air (6 feet tall, 30" inseam). I ride with either foam earplugs or earbuds and music - both easily quiet the wind noise making day-long rides possible. (Rarely is my iPod volume over half way up.)
I recently added a flip screen from Touratech. It's meant for the F800GS, but the bend in this unit and the bend in the KTM screen is similar, so it latches on and works very well for me. Up to and over 70 mph more weight on my chest is reduced, while my helmet remains in clear air.
Here it is on the 690...
Up to about 45 mph, I can actually ride with my visor up and no sun glasses without my eyes getting too much wind, starting to water, etc. Awesome for slow work or around town in the evening. In fairness, I try to always ride with glasses just for the added protection, but its proof to me the small clip on screen was working. :)
It slips over the top of the windscreen and clamps into place. The lock deactivates the clamp, making it extremely difficult to pull the unit off the windscreen due to the rubber pads gripping the tinted windscreen. You can adjust the angle slightly by adjusting the pads on their bolts. Mine was great from the box.
I was considering the Lynx unit, but on the 2012 models you need to relo the turn signals, which starts to make that swap a more involved proposition, not to mention adding yet more money to the project.