Hi! 

So I just finished Grey's genderswap event, and gotten to the point where I choose to either keep him as a woman for good, or change him back. I'm sure this will greatly affect the storyline, so I'm kinda hesitating atm. 

I wanted to know your opinions. and which option would you pick. Thanks!

That depends on your choices permit unless plan on redo game add grey one harem circle or not if you into that thing genderswap.

Male Grey has no noteworthy events, while female Grey has several scenes, some together with other girls. Therefore, from a content perspective, it'd be smarter to keep Grey as a girl.