Actually, when i've gotten rentals on travel (no treatment of any kind), i can just squirt some rainx on the winshield and let the wiperblades move it around. No wiping or anything - and it does a great job over your typical untreated rental car window with horrible visibility in the rain.

Never heard of the other stuff mentioned. Although it may be great - how much better can it be? I'm assuming you mean it lasts longer. With Rain-x, at avg speed in fairly heavy rain, I don't need the wiper at all.