Hi all,
This will be my virgin post here on this forum. I'm not new to this detail scene, but definitely no pro..unlike many of the gurus here. I could only stay in the dark and lurk around.

But since I just had my first hand experience with UPP applying on top of my 3 layers of Zaino, thought I'd offer my $.02.
Just little background info about my detailing exp., I've been through some of the most popular brands of wax and polymer sealant out there...from old school Zymol, Klasse, Meguiar, P21S, Zaino, Liquid Tech, Trade Secret, Souveran wax, and UPP.
I purchased UPP as a substitute for Zaino, and use it as an alternative to Sourveran wax for my daily car. At first I used it on my Ti Gray Volvo, but wasn't too impressed with the shine. More or less on the same level with Zaino. However, it was probably the most long lasting polymer sealant I've ever tried!! It The volvo went through Pinnacle Clay -> Medallion PPC-> AOI -> then UPP.
At the same time on my wife's straight black S class, I was using PC -> Menzerna Intensive Polish -> Men. Final Polish (some areas with AOI) -> Souveran wax. It was probably the best result I've seen on that car so far. But using SW was just provent to be not practical as it attracts dust like nothing else and just not that durable. So I finally decided to switch back to Zaino on the Benz just thought to give it a try even though I knew it wouldn't have the same depth as the SW.

Man...was I disappointed. Just like others said, Z5 didn't do jack. I've tried couple layers of Z5 and it couldn't take out some swirls that I missed when I was going over the car w/ Menzerna polish. Then after 3 layers of Z2, it was still disappointed. Gee...even the acrylic look wasn't all that impressive at all.
Then today, I just decided to give UPP a try. And just to prove that all polymer should be competiable, I didn't want to buy that BS Zaino was selling..."Not to use our products with other brands.." LOL..:beat They were right...UPP couldn't go on top of Zaino without leaving subtle cloudy streaks, which could only be seen from some angle. It took some serious elbow grease to get them out.
But the good news is...
HOLY COW!!!! UPP rocks on black paint!! Even the paint has no metallic in it, the UPP looks A LOT shinier in terms of acrylic reflection, and it has the wet oily look that's very similar to SW! It's the best polymer sealant I've used to date. Zaino just got owned. :mohawk Also from the past exp with UPP on my Volvo, I know for sure it will last for a good long time.
I'm ditching Zainos for good. Overpriced and so-so performance. Then again, it's pretty subjective...don't want to offend any Zaino fan. But after going through 3 bottles of Zaino and countless layers of them on my other cars, I think I can make a very fair judgement.
Sorry for the long post...I'm just a bit too excited with how UPP turned out.