I second the Madstad vote. I am running a 13" Madstad shield on my '14 XC. I do run the full hard lowers and upper air controls found on the tour, and with the stock shorty the buffeting was terrible as well. I also tried the Victory Flip windshield, no go as the buffeting still killed me.
I ran the 11" Madstad for a while, but found I was always running it in the full up position, so I decided to swap out for the 13" and run it slammed all the way down. It looks much better as the gap along the bottom is minimized.
With the Madstad I get no buffeting all the way up to freeway speeds and beyond. You do still get quite a bit of air in the face and around the head, but it is much calmer.