The Dublin/Pleasanton school situation is considerably better than in Fremont -- and always have been along with the rest of the 680 corridor bedroom communities.
Fremont schools are a very mixed bag and while they've improved recently thanks to gentrification they're not fantastic historically. There are still quite a few moderately poor schools mixed in the Fremont district.
Yes, like I said it's a mixed bag. Mission San Jose has very high scores but others like JFK High aren't great.
Unlike Fremont, all schools in Pleasanton have excellent scores. There is no concern of rolling up into the wrong schools depending on where you live, availability, etc.
http://www.schoolandhousing.com/mobile/
Mission San Jose in Fremont is one of the top 10 public schools in terms of API & SAT in the state of CA.
http://schools.latimes.com/sat-scores/ranking/page/1/