I was in your same situation so I tried both. Klasse AIO is about the best protectant on the market, easy to apply and very easy to remove. Protects and hides imperfections very well. The Klasse is excellent and hides imperfections (Zaino does not) and protects very well, but Becuase of the SG (second step), it is a bit more trouble to apply and remove. Actually... real hard compared to Zaino, even using a QD to help.
Zaino is the easiest product to apply and remove, has a super silky butter smooth finish and stays on for a good long time. Zaino does not hide any paint imperfections and the Z-5 DOES NOT, I repeat DOES NOT, hide swirls, I dont care what the bottle or the company says, it just doesnt work, even after 5 layers. Now for what I hate most about Zaino, the dust......Zaino attracts dust like nothing I have ever used. Even using their Z6 QD the dust attraction is unbelievable. All things considered, I stuck with Zaino and sold the Klasse, Its just to easy to apply and I LOVE how silky smooth my finish feels after using it. The shine and protection are about the same with both products and I notoiced no real difference in shine on my metallic Indigo Blue Chevy Avalancvhe. I am not a "Zealot", so I believe my opinion is a bit more neutral than some others but I still recomend it.