Agnieszka - Perfect Polish
Listen carefully, she has the eastern accent too, though much more slight than Oksana.
She says 'uo' instead of 'o' e.g. rozmuowa', 'muoże'. She sound like people in Białystok.
I'd say that her Polish is ok but her pronunciation has some regional (eastern) shade.
Kathy
A foreigner, makes grammar errors. May be difficult to understand on a low quality voice line.
Cinek