Weekend classes at German School of the East Bay (GSEB)

Hello! I have a 6 year old who is interested in learning German as an extracurricular, and we're looking into the German School of the East Bay (GSEB, in Emeryville) Saturday class for preK-K. I'm not finding much in the way of recent reviews/feedback anywhere, especially re: the weekend class specifically (as opposed to full-time enrollment for school). Does anyone have experience with the program? We especially want to know things e.g. safety and adequate supervision, thoughtful curricular design, whether you find the teachers attentive to students' needs and experiences, etc. 

Thanks so much in advance to anyone who has experience they'd be willing to share!