I'll throw my $0.02 in for this.
I dont like Zaino. It looks killer, beads great and is super easy to apply, but IME, the durability is on par with
NXT. I cant get it to bead on a ISO
50/50 wiped surface over well prepped paint for longer than say a month, GARAGED.
I much prefer #21.
Z-8 on the other hand, is worth every friggin penny, but IMO, I wont buy Z2 or Z5 again.