Yep, done to death on many times already. TBH I've tried a few and now run with the OEM normal screen on the lowest setting. For me it gives the least buffeting of the lot. I have noticed a few things make a difference believe it or not:
1. Following traffic, especially larger lorries or caravans etc. Seem to get stuck in a vortex which is a right pain. either drop back or get past.
2. Having my 52ltr trekker on the back. If I have nothing or a smaller 33ltr one, then it seems to be far better
3. Having a passenger seems to muck things up a bit as well.
4. Helmet style. My GT Air made a big improvement over my Arai. I've used Arai for years but now use the GT on the CT. Arai on the Tuono
Of course none of these are a real issue as legal, or slightly illegal speed, lets say up to 80mph
You are correct about the Duke. I have a Tuono with a screen the size of tuppence and no buffeting at all