I've ridden without much wind protection most all of my riding life, but starting to get older I guess. I've had the Roadster screen before and I didn't like it, just too much buffeting, even with the lowers. Also, at a stop, all the heat from the radiator rises behind the screen and back on to the rider!.. I've had the fly screen ever since I bought my Rocket, and with my paint job, it looks awesome and does great blocking the wind from your chest, keeping you from feeling like a parachute.
I'm thinking the Summer screen is shorter than the Roadster screen and may leave a cleaner air stream at helmet level,.. and may not catch all the hot air from the radiator that the Roadster screen did..