The smooth lines of the Z give it a liquid look. Gloss finishes compliment that look. The black stain will give the car an unfinished look to it (primer like). Cars with more angles and sharp corners look better in black satin because the color doesn't accentuate those sharp corners and lines.
"The 300ZX Turbo is a dance; it's a song; it's rolling, roaring automotive art. There is no color that doesn't suit it. There is no mood-lifting chemical substance it can't replace." - Automobile Magazine