I thought it was inconvenient to use for the first time, you wash the car, then polish, then wash again before you can put it on. Then apply Z1, apply Z2, wait an hour, buff off (OK, this was before ZFX).
The ability to layer was nice, but then you coudn't use any other product. Need to use the Z6 as a QD. I didn't like the idea that you had to use only zaino products.
I just got tired of it.
Now I use primarily Mother's Reflections. It's available off the shelf, cheap. It lasts a while (maybe not as long as Zaino though). If I want, I can top it with S100. Or, I can QD with Meguiars (or any other QD I happen to have around). I don't have to go over the car twice, or do 2 washes.
As far as looks, I think the Zaino looked pretty good. But then again, so do most other products out there. As long as you do the proper prep beforehand, you car will look good.
Dom