Title. I'm thinking maybe Miku because I thi k she's just easier to use than a lot of Vocaloids. Maybe Rin since thats Mothy's favorite Vocaloid so he'd probably want to learn how to tune her as best he can? I genuinely have no idea :/
In a sense which Vocaloid do you think he's the best at tuning overall and you like him tuning because of that. I acknowledge most of you will probably be biased ever slightly so :/