I also noticed when using it that Zaino dried faster than with the Z1, Z2 combo. It took about 20 minutes tops on a 70 degree day. It could be my imagination, but I did notice a gloss increase too over the existing coats I have on the car now.
The maximum amount of coats you can put on at once is 3. I talked to sal about this a few times. I turns out that it becomes so slick (you are not going to believe it) that it has trouble bonding to itself after 3 coats. Now waiting even a few days to add another coat would be fine, and it would layer on with out a problem. Washing the car, rubbing with towels, or the wind resistance while driving will abrase the polish surface enough to layer on additional coats.
You have to hand it to sal. He took his time with this product and got it right. He tested it for a long time both in the lab, and even had some of his customers test it for him under different circumstances to determine optimum usage. He could of easily claimed that one could do 10 coats in a day, after all that would sell more product, but he is all about results and getting it right.........