NJ top schools are more diverse than equivalent top schools in the San Diego area. No crapola like Mello Roos, where a newly-built community can buy itself its own gated school.
I went to a highly-rated high school in NJ, but shared a school with children of immigrants who barely spoke English, children of blue-collar workers, as well as children of wealthier families. Not all families places as high of a value on education, but the diversity was actually a good experience in and of itself.
There isn’t as much economic self-segregation in NJ as there is in San Diego. Thankfully!