I have the CalSci in medium. I tried the stock screen and a tinted Vario MRA (with the little kicker). Both allowed too much wind on my noggin. After some research I opted for the CalSci. I'm 5'9" so the medium was just right, the slipstream rides about 3" above my head. My sight view is still over the top if the screen too. Riding behind the CalSci is very comfortable. The bulk of the wind is deflected but there is still enough air movement that keeps me cool in the summer. Also there is no buffeting.
If you order one from them, you need to specify if you have hand guards or not. I did not specify and they sent me the wider screen so I had to take off my hand guards. CalSci said they would exchange me but I like the coverage of the wider screen. I plan on getting a bar riser anyway, then I will be able to reinstall the hand guards.
Also just a note, if you look closely at the pic, I painted the lower part of the screen so it would hide the mounting hardware. Now the screen blends with the dash nicely.
Good luck on your search.
2011 Versys 650
Even a fool is thought wise if he keeps silent... Proverbs 17:28