*$$$ I guess
*$$$ I guess
San Jose is also not really a city in the way SF is. I used to go to conferences there fairly regularly. (Intel's IDF was there for a number of years before decamping to the Moscone.) Was there for another event a few years back and I was sort of surprised how relatively run down a lot of the downtown still was. Some new restaurants and the like but not really what I expected in SV.
They don't particularly have long commute times for an area the size of the Bay area:
http://www.governing.com/gov-data/transportation-infrastruct...
This is also a function of where the employee lives. If you reside in say mountain view, your commute likely will be under 20 minutes to the vast majority of South Bay tech companies. Less true if you live farther away, say in South San Jose.
Consequently, SF companies have the same problems: the people without kids are nearby, but the ones with kids tend to be far away and are harder to hire.
There's no optimal location, unless you specifically are trying to select for junior vs. more senior talent.
> where the rents are close to what they'd pay in mountain view
Having just moved, I can assure you that Mt View rents are significantly lower than SF. For "nice area" (1990+ construction, convenient) 2-3 bedrooms, you are looking at something like $4+/sq foot/month in SoMa vs. ~$2.5/sq foot/month in Mt View (Palo Alto is considerably more expensive than Mt View and gets close to SF prices). That said, the reduced ability to live without a car cuts into the price savings significantly. (e.g. my family had to get a second car after moving)