That's a tough one. Some exposed zippers are cool aesthetic statements. Most exposed zippers that I've seen are a tailoring shortcut, requiring less time and skill than setting in a hidden zipper - which means it can be produced more cheaply by a clothing manufacturer. I think it's a case of "you know it when you see it". I have a black Ann Taylor jersey maxi skirt that I thrifted years ago, and it has a gold zipper up the side, and it's somehow so good, it doesn't look dated. I think it's because the zipper itself doesn't look cheap or plasticky, and because it fits the slinky mood of the skirt.
Setting aside all dialogue of "dated" vs. "back in", if you genuinely aren't enjoying this dress, I say pass it along to someone who will. But I wouldn't rely on this year's NAS to make that choice for you, unless you really like what you're seeing, and think this dress can give you a similar effect.