Yes, I love Sonia. The only criticism I have of her is putting her feet on one of the girls faces, Penny I think her name was. That was uncalled and not the least bit funny. Other than that I have no issues with her.
People accuse her of being patronising comparing her hosting style to that of a teacher speaking to prep students but it doesn't bother me in the slightest. Let's face it this show is designed to pander to school children an whenever she talks like that I'm not assuming she has adult viewers in mind at that particular moment but school children who are fans of the show.
As much as I prefer Gretel over Sonia I do agree however that Sonia would suit the today audience of Big Brother better then Gretel. Like you said, BB this days is targeting school children more