@Datas_Cat_Spot
Who was "better utilized" is a hard question in my view, but I think it's clear that Quark was a more fully developed character.
Guinan appeared seldom but always gave insight to characters when they most needed it. She was enigmatic, and cool, but not very fleshed out.
Quark was more realized as a character - more complex, more highs and lows, more emotions. I didn't like him much, but he was more "interesting" to watch.