In one study of women aged 18–35 who were in heterosexual relationships, using sex devices during partnered sex was associated with higher ratings of arousal, satisfaction, and orgasm intensity. That is an association, not proof that a toy by itself improves sex: the study cannot show what caused the differences, and its findings cannot automatically be generalized to everyone or every relationship.
If you want to try one, the conversation can begin with curiosity rather than a purchase: “What might you be interested in exploring?” Talk about what feels good, what does not, and how to stop if either person's experience changes. Pleasure is not a competition or an obligatory outcome. A good experience is one in which both people feel safe and free, and can change their minds at any time.