So it took me a looooooooooooong time, but I finally have my own shorty. Bought one of those spare windshields on 11-09-2013. Since I have an Xcreen clamp-on, adjustable windscreen extender, I need the top to stay straight, not round. And others say a 4" drop is needed. I went for a 5" drop, since I will be using the Xscreen with it and have more flexibility/options with it.
Drove to my friend's house and removed my old shield. Taped it up, marked 5" down, cut it with his band saw. It was surprisingly easy and effective. Then on the scrap I tested using a torch to try and melt the edge nice... um, that is not going to happen. The plastic either burns or bubbles or discolors. If I just wave it around a lot carefully then nothing happens. So we used an air powered handheld grinder with a plastic wool (?) pad and made the edges smooth and tapered.
It is far from a perfect cut, but it isn't that bad either... most people would probably not even notice. Only driven once with it, yet, and that was tonight... and it was 70F, so I had it fully up and with the Xscreen half engaged. With it down- wow! So I think this might go a long way to helping with summer overheating. When the lows start to get back into the low 70's again, it will probably be time to switch back to the full screen.