Not only is Sage far more attractive than Quinn but she's also a much better person. Quinn has depth but that doesn't change the fact that she's a fundamentally shit human being, an abusive narcissist who manipulates everyone around her as easily as she breathes. She's interesting but I don't like her at all.
I don't see it quite like that. Quinn is already a hot girl in terms of looks. Quinn's personality, so she has a crude sense of humor, I could overlook. But the lying, using people, and of course the criminal side of her, make her a no-go for me.
And therein lies the reason why Quinn falls in love with the MC. As you wrote, Quinn manipulates those around her. With what? Sex and drugs. The DIK MC has actually lost because Quinn will manipulate him. I don't play a DIK MC, but what I've read from you suggests that. He's going to be her bodyguard? In EP8 the MC can even have a gag in his mouth with "Slave" written on it. Quinn makes the MC a dog, a toy. If she loses interest in the MC because, for example, someone is more interesting to Quinn, she will abandon the dog and put the toy in the corner.
But a CHICK MC is not manipulable by her in that sense and that is why the MC is interesting to Quinn. The CHICK MC becomes someone equal to Quinn, someone who is Strong and has a shoulder that Quinn could lean on. I even think so that's the redemption path for Quinn because it makes Quinn see the MC as a kind of father figure. Her father, Rox, was very influential on Quinn in her childhood. So I think so that the CHICK MC can have a positive influence on Quinn in the future.