I've tested both ZAIO, followed by Z-2 pro vs DG 601 followed by DG 105. I thought that the Zaino side was a tad bit slicker. Both sides held up very well for 6 weeks. After this time I couldn't take it anymore. I had to wax the car. So I chose to go with another wax. The Clearkote line. It too lasted 6 weeks, and was going strong when I decided to put another cote on.
I like Zaino and have most of their products ZAIO, Z-2 Pro, Z-5, Z-8, Z-6, and the leather stuff. To me the Zaino & DG leather stuff smells the same, and the other comparable products work the same. JMO.
It was said on another web site a long, long time ago that Sal from Zaino and one of the Bailey brothers shared technology in the past. Supposedly Zaino car wash before 2000 used to be red and cherry scented according to what I was told.
Both companies are to close together not to be either one in the same minus a few steps here and there (product wise).
That or someone took one of the many formulas of the opposing company, hired a chemist and found out what exactly what was in the others formula, and then made their own, and then tweaked it a little to their specification.
It's not that hard to find out what's in someone's formula, if you have enough money, hire a chemist and want to know.