A while ago I ordered Winglets from the R1200GS Adventure to install on my bike. My R1200GS is the 2010 standard GS model which means it has a smaller windshield than the Adventure and no Winglets which reflect wind that comes around the low sides of the windshield.
I read a lot about those Winglets - people say they reduce buffeting at the helmet and they also help in protecting the body better. Both good things, I was mainly interested in reducing buffeting as protection is not that important here in mostly sunny California.
Today I had a chance to install them. I used a small drill to drill the holes from the inside of the fairing so that I didn't have to take the beak off. This worked well, one hole got a little bit "dirty" with a not so clean cut edge, but it doesn't matter as this is hidden by the rubber washer that sits between the Winglet and the fairing. My 2010 model also has the same metal fairing support under the plastic as the Adventure model, so I really needed to hit the right spot for mounting. No "free form align with fairing" kind of thing as it was with the 2009 and older models. All went well and I got them installed using hardware from the hardware store ($5 instead of $35 from BMW).
Now, do they work? I think so, yes. It's hard to say for sure as it is always hard to find a stretch of highway without turbulence from passing cars in the area here but I have the impression that the air behind the windshield is much calmer now - less buffeting. Yeah! That's what I wanted. So far I still use the standard windshield and moved it to the lowest position. With this setting it is still fairly loud as I'm hit about chin level but the air is pretty clean when there are no turbulences created by cars around me. So far I really like this modification! It was easy to install (but it's kind of scary drilling into the fairing of a brand spanking new bike!), not expensive, around $70 including hardware, and works well. You can't say that about all modifications ...
I will give it a bit more time to decide whether I actually want a different windshield or live with the stock one. As said, it's not getting too cold here, but I still might something with more protection that also makes the ride quieter just for longer trips.