Here's what my second windshield looked like. It improved my coasting performance (this was before I got the SuperMID, so I have no precise numbers), but had problems with fogging up on the inside during cold wet weather and the visibility through the clear vinyl wasn't optimum.
When I get the time, I plan to reglaze it in lexan, design a better defogging system for the inside of the glazing, and install a low drag windshield wiper (for use when I'm stopped, when I'm moving the rain mostly flows around it without hitting).