If you take someone final save you will miss all the fun with each girl, some stuff can't be repeat you need have save before advance the story of the girl for the action she will do that you want access without do the whole game again ^^
Personaly i enjoy this game
no need excessiv farming, one time you found one girl you can win the other will follow (and before that you have the story of each girl to entertain you during the losing chain phase. i hope this don't count as a spoil, i just try to gave the feeling the game has gave me^^)