I'm really not trying to be an ass here, but I can't help but question why so many people seem to think they can get a quick and painless answer to questions about some magical "BEST" product. We see the same kind of questions about pipes, lubricants, seats, bars, electronic gadgets, etc., and of course there is no single "best" for those either.
Windshields are a highly subjective choice. Some like to look through the shield, others prefer to look over the shield. Some 6 foot tall folks have longer torso's and thus sit taller in the saddle than other 6 footers (and of course some seats sit lower than others). Some wear helmets, and some don't. All of these things will affect what you may consider to be the "best" windshield. And some of the buffeting may not be directly related to the windshield height anyway. Some can be traced to the air that fills in from the sides and up from the front and sides of the tank.
Contact site vendor Freedom Shields and talk to them about how to select a size and type to fit you and your preferences. If they still have the same policy, as long as you leave the protective film on the shield you can try it on your bike and return it if it doesn't work for you. Others may also offer the same thing. Ultimately it tends to come down to trying some different shields until you find something you like. It can be an expensive process so I understand wanting an easy answer, but there really isn't such a thing.
JMHO - Jerry