The Bigboy is at least an inch up from stock (new stock, not old stock).
The stock height (15.5") Clearview on my IS with Bigboy is the perfect height shield for me at 5'9", but I only wear half helmets and corrective lenses to see (that the state requires I wear to drive/ride) (and I like windshields), but easily look over it. (No vent, and I plug my fairing vent because I ate too many bugs through it.)
When I ride a no shield or low shield with half helmets, my vision blurs with wind much over 45mph, and I cannot see. And I get bugs and dirt and the occasional rock in my face/eyes.
I can't stand full helmets (though I have a very good one, it's only been used in freezing cold).
But with a full helmet (or modular folded down), I guess you can ride as short a shield as you want.
This is probably not the advice you were looking for.
You should probably decide whether the shield you get will be a summer-only (shorter) or stretched out to three season (taller).
Whatever you get from Clearview, remember to leave the plastic on it all the way through installation and test ride (and don't bugger it up any), and then it can be returned. Once the plastic is pulled off, it's yours.
If you enjoy night riding in SC in summer, you probably know you kill millions of buggies.

A lot of guys discover all or some of the 4 anchors in the fairing are all buggered up (or spin in the plastic). Ordering 4 new ones before the shield arrives is a good idea. Inserts for fairing, Honda part #90316-MJ1-000