State law wisely requires district elections for city-council instead of citywide vote. Sunnyvale resisted this change for years; they could have put council district elections to a vote of the citizens but they did not. Instead they offer Measure B which sneaks in unrelated issues of directly electing a mayor and term limit changes. Those issues should be voted on separately.
Why the push for directly elected mayor? There is no scientific evidence to support a theory that such a mayor is more effective. Hardly any small South Bay cities have directly elected mayors (Palo Alto, Mountain View, Cupertino, Los Altos do not).
Directly electing mayor is expensive, which means big money donors will win and grassroots candidates will lose. So the developers and the city will continue to increase congestion and decrease quality of life.
Vote No and help Sunnyvale get seven district-elected council members and no directly elected mayor.