About West Contra Costa County Public Schools
Since in your district 6th grade is a time of school change, you might want to consider a transfer to a school in the West Contra Costa district, where 6th grade is still in elementary school and there are a couple of K-8 options. In our experience, this made the social component a lot less stressful. It is also so much easier on the 6th grade students to remain with one teacher rather than having five. Good luck.
I agree with the previous poster! Schools in West Contra Costa and San Leandro/Hayward may not have great test scores, but many of the students do very well and the schools are very diverse. In fact, Korematsu Middle School in El Cerrito is the 4th most ethnically diverse middle school in the entire US. The basic curriculum is the same at every public school in California.