My Tulsa is specifically designed to wick the rain like water off a duck's back feathers, due to the perfect aerodynamic shape/angle. Over 45 mph I can ride for hours in light rain or heavy downpours, with no visability issues. Previously, I had always felt a windshield you look thru was dangerous, thus kept them adjusted in a low position. The Tulsa not only affords way better protection due to its height and width, but unless the rain is particularly hard, allows me to keep my faceshield open for better breathing/less fogging! After riding with the "look thru" Tulsa for 5 years on my GL1800, I like it just fine and have no plans to change it out. I ride in the rain regularly, and love the experience.
The top of the windshield should be 1-2 inches below your line of sight.
Lower the windshield, raise seat.. whatever it takes.
But you really don't want to be looking through the windshield for any serious long distance riding.
It's a WINDshield, not a RAINshield.