the bike will still be stable, will corner and brake the same
on the interstate when you get behind a truck it might feel like you are being blown around a bit more
the biggest difference is a windshield acts like a speed brake on a plane - you will need more throttle to hold the same speed, when you shift the bike will slow down more between gears, then you let off the throttle at 70mph the bike will slow down faster on its own.
For me the biggest difference is you dont feel the windflow across your body, so you lose the feedback of how fast you are going, and if you are riding in the sun on a hot day you will be cooking in your own juices.
I have windshields for both my bikes. They stay in the garage unless Im going to be riding 70mph or faster, which I almost never do, or unless the temp is below 50F (late fall and early spring) when Im commuting to work. Under those conditions a windshield is better, but it sucks the life out of the motorcycle.
The biggest issue with traditional windshields is head buffeting. Its not just wind hitting your helmet, its your helmet being in the turbulent air where it breaks from being smooth laminar flow off the edge of the WS, to being chaotic. Its like your head is in a paint shaker, your eyes are vibrating so much you cannot read road signs, and your brain is hitting the inside of your skull literally giving you a mild concussion in a manner of minutes - you will know it if it happens, and you CAN NOT ride with head buffeting.
If your windshield is about the same height as your nose or higher you can adjust everything to get rid of buffeting - if its too short you cant, then all you can do is duck your head down lower while riding.