Not even a day yet...
Not completely sure yet, but she seems slightly better the Mia but slightly worse then Ayra, still, to me. Ayra's built in Flashing Blade just allows her to deal with so many things when combined with her insane special. It free's up her A slot to use Distant Counter or to just boost her stats beyong Karla's. Her defenses are also way better then Karla's, making her better on Enemy phase.
7 added damage is kind of nuts, though.