Windshields, like seats, are really a matter of personal preference. Both length (height) as well as width will make a difference in performance, as will flatness and/or rake, and whether the top edge has a Euro 'flip'. Into this 'mix' you can also toss the possibility of top edge 'add-ons' like an adjustable X-creen, which (like the 'flip') increases ability to divert wind flow. Likewise is the question of whether or not you need vents. Further, is your shield already adjustable (up/down) on its brackets? Shields that suit some may be hated by others. The solution will first depend on whether you're happy with your seat position. Start there!!! If your butt is happy, then look to making your head/torso feel good. If you begin with your head, pick a suitable shield, but then change your seat, you may mess up that original shield choice if you have changed your sitting height and geometry relative to your bike. Once you're happily well seated, you need to decide whether you want to look over, or through, your shield. That will start to suggest how tall a shield you want. Then, it's trial and error to find one that protects what you want sheltered, and provides flow where you want or can tolerate it. I have a 2017 F3L; I have almost 3 years of looking to find my personal perfect solution. It's an elusive goal, complicated in my case by the need to change seats to attempt to resolve sciatic pain issues. 3 different seats and 6 shields later, I'm still searching, but have found a tolerable solution. It involves a raised seat and both a 'flip' shield and added X-creen 'clamp-on' extension.
In short, I agree with RICZ that a 'flip' will give you added upward diversion of airflow beyond that of a plain flat screen. You also need to avoid/reduce back draft or 'suction' behind your windshield, so that noisy, turbulent air is not drawn around the edges and 'curled' into your face. Good luck hunting. Don't be discouraged. It takes time and willingness to experiment. And remember, you are riding a motorcycle; it's a 'breezy' world. Totally quiet, absolutely calm perfection is not likely; you're not riding in a luxury convertible. But, you can get close to a relatively calm, peaceful 'bubble' in the area just around your helmet, with the heavier turbulence flowing past about 4" away. That's about as much as you'll ever get, at least IMHO. Others may differ. If you find a magic solution, please let me know. I have a couple of spare, very lightly used 'test' shields with only a couple hours use if you're looking; part of my test battery, all in excellent shape, priced right.