Hi Moon - we too looked at Sunnyvale 1 1/2 years ago, decided to buy in Union school district (ZIP 95124) and are overall happy with our choice. Noddin Elementary is a decent school with high API scores, and the houses are generally of a higher quality and a much better value than those we saw in 94087. Los Gatos downtown is a short (and beautiful) drive, and the are and views are _much_ nicer than anything you'll find in Sunnyvale.
As to micro-neighborhoods, you're best advised to stay away from Camden (keep west), preferably west of Harwood, and stay south of highway 85. For value, views and good neighbors, it's hard to beat the blocks bordered by Harwood on the east, Los Gatos Almaden, Chevalier and Leigh H.S. Socially the neighborhood is a mix-- more young families working in tech companies moving in, but still many older folks and some blue-collar; all ethnic varieties, none really predominant. Our block includes people from Taiwan, Russia, Iran, and (I think) Italy.
We can recommend an outstanding realtor if you need one-- super sharp, works extremely hard, and refunds 1% to you the buyer. Email us at t_thibaud at yahoo -- we're looking for more nice folks with school-age kids to come into the neighborhood. Best of luck in your search, t