Let me add to my response. I'm commuting where the average speed of cars is 80mph. If I were in eco mode it's 74mph but cars are passing me. So wind buffet on my chest in the afternoon. In the morning. Far less cars. Otherwise I'd been happy with no windscreen. Full face helmet does keep wind off your face.
I think I will give it a try with no windscreen and see if I like it. I would not ride without one on my last bike , but it was a cruiser and I wore a half helmet. This will be my first experience with a full face.
Just took a trip into the mountains of NC this weekend. This bike is a comfortable ride mainly because of the position the rider has on the bike. The seat is a little flat so it wont have all the padding that most cruisers have. The wind is going to be a factor, but this is a naked bike, your going to feel the wind. It's not unbearable and if you're cruising in the 70's or 80's just hug the gas tank. I do not have a wind screen and do just fine.
One thing I would suggest is to get a full face helmet, it will help out a lot with the wind in your face, and on a naked bike it is going to be your only face protection.