Apples to oranges was my first thought. Guinan is good at listening, helping to sort out someone’s thoughts, and if needed saying that there is a path for someone to follow. Quark is about that profit, and when he gives advice it is direct, not subtle. Sometimes accompanied by an insult. I think both are good characters, but Quark is definitely more well-rounded and developed. Over time, little is learned about the El-Aurians from Guinan. A lot is learned about the Ferengi from Quark.