Personally I'd go for the semi-gloss, but then again, I'd paint the hood and use semi-gloss stripes as well.
In the grille and tail area, gloss will draw attention to the shape of the area. One of the coolest things about the front of the AAR, to me, is that it's semi-gloss black so the grille seems to be non existant. If you gloss it, you'll catch more reflected light and it will show up more.