I have a 13 King with a recurve shield. The top is at eye level for me and no buffeting pretty much at any speed. I've ridden coast-to-coast a couple of times without any issues. Once with just the windshield and another with a removable batwing. The batwing does provide a bit more wind protection though, and also has a recurve shield.

I ride with a half helmet mostly and a FF during cold or rainy conditions or if I don't want my face to get a suntan during long rides.

 

FWIW, before I tried the wind splitter, I tried 2 shields from Freedom Shields. an 18 and a 20. Both with the recurve. The 18 I could just see over, but the buffeting was horrible. I threw the 20 on and had little to no buffeting. Almost dead quiet. But, now I was looking through it. And I didn't like that. Didn't find anything that worked for me until I went with the vented. again, YMMV, but just letting you know. Oh, and I wear a Shoei Neotec with earplugs.

 

I’m a short rider, with a long trunk.

The stock windshield was right at eye height, which I found annoying.

Trimmed it down, to look over, and it rattled my skull most violently.

Went taller, which I look through, and the head buffeting was gone.

 

I have an 18” LRS windshield now and just ordered a 20”. The LRS are 1/2” shorter so I’ll see, it should put it right below eye level. The only wind I’m getting is on top of my helmet above 50mph.

 

I just bought a windshield frame/hardware of of Craig’s List for cheap and it had a new shield on it. It was a 20” HD off a 2018 RK. I popped that on and took it for a spin and absolutely no buffeting at all up to 65.
By the measurement that is recommended the 18” was supposed to be it and with three 18” windshields, one a recurve, I had buffeting from bad to annoying. With the 20” I can look over it as long as I sit up and don’t slouch. That was the first time I have road with a windshield and not had blurred vision above 50.
I already ordered a 20” LRS and it should even be better. Although the 18” LRS didn’t work out at above 50 they do keep it calm behind the shield so the 20” LRS should work great.
The only thing I would say is be careful not to overestimate the ability of a recurve. Measuring the way I was told the 18” LRS should have worked.

 

I cut my stock shield down so I'm not looking through it, got the fangs and triple clamp deflector, no buffeting. Fangs helped the most.

 

I am convinced that serious head vibration from a helmet with a big visor on it caused me to develop a detached retina while riding a windshield-less bike at high speed. If your vision is blurry, be sure to find another setup...

 

As I said before this is my first bike with a windshield and in four years I never rode over 55 without my head buzzing and my vision blurring with three different 18” windshields. Now with a stock RK 20” and fork fangs no buffeting.
I can’t wait to see what it’s like with a 20” LRS.