Now have 498 miles on it and my wife loves it. My 2008 ST 1300 had 30,000 miles on it and loved every mile but wife hated it. Now she rides in comfort and I am trying to figure out how to stop whe wind buffiting on my helment. I do like it!
Cut two upside down triangles low in the Windshield. about 2-1/2 inches wide at the top. instead of straight sided make them curved for a better look. It should allow enough air through to eliminate the vortex buffeting you are experiencing.
Our situations are similar. I recently moved to the wing from the ST also. However, my ST is still sitting in the garage torturing me. I love them both for different reasons, but I can't afford to keep the ST! All the best.
Instead of cutting holes into the windshield, you can just open the vents to equalize pressure behind the windscreen. How tall are you because depending upon your stature, there are different solutions. I'm 5'-9" and dont get buffeting unless there is turbulence or crosswinds. I keep my windscreen at the highest setting.
I too traded my 05 ST for a 2010 Wing and I love it. I have an after market windshield on my ST and it had those triangle holes in the bottom and I found them to make a lot of noise. It was like a whistle.