This is an interesting thread, and it brought to mind a few ideas.
One, I realized I don't use my wipers at all, except maybe to brush off bug guts or something. I've found Jet Seal 109 to be extremely water-phobic, even more-so than RainX which is quite exceptional in its own right (but very hard to polish off a windshield.) My previous 2010 Flex had similar behavior to your SHO windshield, now that I think about it. I chalked it up to a microfinished surface that was privy to not being able to be cleaned like normal glass. Side note, that glass also had an overall haze from what I believe was the laminate in the middle. There was also a rippling effect, which was not pleasant. A good excuse to trade up I suppose.
I don't use many Zaino products anymore but I do remember their glass polish product being out-of-this-world good at cleaning dirty glass. Also smells like tapioca I think.
Oh, and waffle microfiber towels are your friend when doing glass. They'll stop the micro-fuzzies from adhering to the glass after you "clean" it with a microfiber. That, and/or newspaper. For some reason, it works extremely well.