Arrived in 1992. Left in 2001. Lived in a Sunnyvale apartment two years and a San Jose house (NW of Campbell) for seven years.
I moved there for my career, which did very well. I largely hated the valley as a place to live, simply because it's too crowded. I have a low tolerance for traffic. I couldn't stand to drive to the supermarket, let alone go to work every day. So I spent all my time either at work or at home, and went out as little as possible. Lived in a tiny house because it was all I could afford. Hated it.
OTOH, I did meet a lot of lifelong friends there, including my wife. It's the only place I've lived where my geekiness wasn't the least bit unusual and where I wasn't usually the smartest person in the room, and that was refreshing.
Now I live in the middle of nowhere in a 4,000 ft2 house on 50 acres of land, which in retrospect was overreaction to the valley's housing and crowding. It still takes 20 minutes to get to the supermarket, but now I travel 15 miles of country roads instead of seven blocks of six-lane parking lot.
When I go back (I telecommute), I'm struck by the wealth, the workaholism, and the aforementioned number of geeks. I also have the energy to deal with the traffic, get out and do fun things for athe week or two that I'm there.
So that's my advice for QoL. Work there, live someplace else, visit occasionally.
(I still can't think of SF as part of silicon valley. The valley, to me, starts in Palo Alto and extends south. That's less true today than when I lived there, of course.)