I have a small screen, I took it off and was immediately impressed at the feel of the wind and the sensation of having nothing in front of you.
I also liked the look of the bike with no screen.
After riding for a couple of months I put it back on. My daily commute consists of about 40km of expressway, and the screen just made it more pleasant.
It keeps the wind/rain/bugs off my torso, leaves my helmet in clean air with no buffeting, and has no negative effect on handling. It also improves fuel economy.
I suppose every rider/screen combination is different and individual results will vary.
For me, if I was just riding around town and on Sunday rides I would take the screen off again, but for my particular use the screen is staying on.