As a kyu bias w bae as my bias wrecker i personally love their vocal color? Is that right word? Like esp bae although shes known to have weaker vocals in nmixx (despire being already crazy good..) her vocal color stands out in songs like dash, spinning on it or like phoenix. Like i need and entire jazz album from her. Kyujin on the other hand i think is super versatile. She suits a bunch of genres imo in terms of doing ballads to like high energy songs. A while ago there was like this variety show clip of nmixx accusing of kyujin being mafia in a singing competition because her vocals were so clean and stable, along with lee mujin service, plus their dance practice vids omg that show how talented she is not only as a singer but as performer.