Perhaps I can offer some comments, or thoughts, more so than recommendations..... I, too, ride a 2017 F3L. I'm 5' 10-1/2". I have used 3 different shields and am about to try my 4th variation. I prefer to see over my shield rather than look through it, but also like to have much of the air moved above my helmet (and my passenger's) and to avoid most of the buffeting.
I began with the short stock shield with the 'flip'. Since none of my previous three bikes, all years ago, ever had a shield, riding in the full open air was all I had ever known or experienced on a motorcycle. It was somewhat expected that I simply took what the breeze brought. My lady, being a good sport, was likewise accustomed to wind in her face. We tolerated the 'flip' shield, but both of us felt that our ageing bodies deserved a little more comfort. I purchased a 23" lightly tinted F4 shield from Don. It was a real pleasure going off for a ryde following the switch-over. The F4 screen was much broader as well as taller and pleasantly quiet to ryde behind. It very effectively eliminated any buffeting. I likely would have stayed with it but for the fact that my BRP trailering cover, also used daily as an outdoor cover, would no longer properly fit because of the taller, broader expanse of the F4 shield. So I moved on to try a BRP 'Tall Boy', thinking I wanted the option of continuing to use the trailering cover.
Upon reflection, if I had to choose an F4 shield again, which my wife and I really did enjoy for its riding comfort, I would go with a 21" and clear screen rather than tinted. This is simply personal preference. At 23", I found myself seeing over the screen when looking down the road, but through the screen when viewing within 70' or so in front. I didn't like the 'split view' experience. At 5' 10", and preferring to see over, the 21" would have been a better fit. The light tint screen was OK, but I'd rather a clear one next time around. Overall, the F4 is great. I have seen what I believe was a Cal Sci shield on a friend's F3L and he had similar positive comments; he's about my height and his shield was close to the same dimensions as mine, seeming to produce similar results. However, his shield would likewise have meant that my BRP cover wouldn't fit. I did briefly give consideration to a Madstad shield about 21", as mentioned by MagYukon, above; I believe it likely would have given a good result for us, as well as allowing continued use of the BRP cover with its slightly narrower shape. Instead, I wound up trying a used BRP 'Tall Boy' taken from a nearby F3L. Aesthetically speaking, the "Tall Boy' shield has a very pleasing look when mounted on the F3 Spyder; design-wise it's hard to beat.
The 'Tall Boy' pushes most of the air sufficiently above our heads as well as allowing me to see over the shield (in fact, well above it). Because it is narrower than the F4 shield, the wind coming around the sides does catch my arms, and some does come close to the sides of my helmet. My wife is mostly sheltered, but not quite as much as she was behind the F4 shield, where she often rode with her face visor completely open. My sense is that ryding behind the BRP 'Tall Boy' is a noisier ryde than behind the F4. Thus, I'm still looking to improve. So where am I going next?
I have just bought myself an X-creen 'clamp-on' to add to the top of the 'Tall Boy' shield. I also plan to experiment by attaching it to the original stock 'flip' shield. Something tells me that the latter may wind up being my eventual solution - a low, see-over shield that effectively moves most of the air past our heads and upper bodies and gives a sense of peace and quiet when running down the road. If all this doesn't work, I can always simply scrap the BRP cover and revert to an F4 shield - clear and 21", to suit me.
At 6' 2", and wanting to look over your shield, I kind of suspect a 23" F4 shield is a good possibility for you; but talk to Don, and let him guide you. And look over the other possibilities mentioned by others. In the end, a shield (along with its clarity, size and height) is really a 'personal comfort' choice. Good luck!!!
