All great questions. If you are looking for long term stability of a neighborhood, schools tend to be the best predictor. Campbell, if the address is within the Moreland school district have excellent elementary schools but may not have the best middle and high schools compared to Cambrian. In particular, the 95117 (West San Jose) and 95008 zip codes have homes in the Moreland school district.
Cambrian schools that are within the Union school district have some variations but are the most solid in regards to K-12. Carlton, Oster, Guadaloupe, etc are all good elementary schools. Dartmouth for middle and Leigh High School. You can down load district maps and get a better feel. In general the zip code is 95124 but also some are in 95118.
Willow Glen offers one of the best communities and is most convenient to Silicon Valley central. However, only the Booksin elementary school is high scoring. The middle school and high school are significantly lower than any of the Union School districts. http://www.unionsd.k12.ca.us/ (look toward bottom of page for map.)
I agree with Patrick that buying a home should be a complete decision in regards to lifestyle, commute, community, and schools. Also recognize that a "zip code" does not guarantee a placement in the desired school. Due to the popularity of some schools, re-distribution of students to other schools can occur. It is always best to check with the school and or school board before making a decision.
A great resource for looking at all grades on a map - http://www.schoolperformancemaps.com
Each area has its strong points. In the final analysis, it has everything to do with where and how you see yourself living. Is commute a consideration? Where are you commuting to? What types of recreation do you enjoy? What shops do you like to go to? Traffic patterns should be considered in relation to where you work/friends/family/activities/etc... For example, Willow Glen can be difficult to get in and out of during traffic times because of the 280/Bird Avenue/87 interchange. If you are in the outer areas of WG away from the downtown you can have access via17/Hamilton.
Even if kids/schools are not in your scenario you should still consider them in any purchase. Santa Clara County has a mix of schools with varying performance. The areas with the better schools in all cases out perform neighboring areas with "fair" schools. Especially since you are looking for a SFR and are looking at this as being a temporary (7-10 year) situation, then I would suggest looking in better school areas. It will pay at time of resale as the home will be less vulnerable in a down market and more desirable in an up market. There are a couple of areas in Willow Glen that match those criteria. Cambrian is desired by families with children because of their strong school performance. Campbell is mixed. The area around the downtown not so much, but the areas around Westgate and Saratoga doing well.
I am a SF Bay Area native and grew up around the neighborhoods you are considering. Please check out my website for additional neighborhood information and information on my services.
All the best,
Keller Williams Realty