BilltheCat- Welcome to Autopia. Your handle makes me want to say "ACK PHFFFT!", yeah, I loved Bloom County and Bill was my favorite character.
*I* think that you WOULD (especially as someone who is familiar with Zaino) notice the difference, especially on colors like black, red, etc. Now whether or not you'd PREFER the difference, I can't say.
You're right, it's hard to verbalize this stuff.
I myself find that Zaino frequently does, *IMO*, lack the "depth" that *I* prefer especially on certain colors (I'm NOT slamming Zaino! Lynn and Brad use Zaino and I think their cars look great). I'll sometimes see a car and think "that's Zaino"- I can sometimes spot it and I don't even USE it. *I* just happen to like a very different look in most, but not all, cases.
Yes, it IS a subjective thing. When I look at a Z'ed car, I think "very reflective"...like the light is just BOUNCING off of it; to me it's like a (literal, glass) mirror. Sometimes it's SO reflective that it makes it difficult for me to appreciate the car's lines. When I look at a car with the "old school carnauba" look, it's like a deep pool of paint that you could fall into, like a bottomless body of water. Still reflective, but not in a "hard" way, I don't think of things "bouncing off" but rather "sinking in". *I* find this more often than not ENHANCES the lines of the sort of cars I like.