i've lived in northern california (east bay) most of my life but i also have lived near san diego, which is almost about as south as you can get in cali. but i'm biased and think the bay area is one of the best placest i've ever been to, so...
what i love about the bay area:
-good transportation (muni, bart, caltrans, whatever)
-diverse. we have every culture which means art, theatre, food, music, etc, obviously this is in most major cities as well, but i've traveled to quite a few big U.S. cities (austin, seattle, new york city, honululu, las vegas, phoenix, los angeles, chicago, etc.) and the bay area is definitely the most diverse...they're always something going on and i think it's a cool place for a liberal perspective.
- mild weather. aside from the demographics, the climate is diverse as hell even from san jose to the east bay (san jo is hotter by like 10 degrees most days), east bay to san francisco (it's windier in the city, and obviously more foggy...it's what they're known for), and even from district to district in the city (the sunset, near ocean beach opposite the bay bridge is always foggy and literally 10-15 degrees colder than downtown, which tends to be really sunny and nice), of course there's marin county and the peninsula, etc. but it's spare you the weather report, haha...anyway, it's doesn't snow and doesn't get crazy humid, so it's nice if you're steering away from more extreme climate changes seasonally
-good schools. cal berkeley, stanford, USF, UCSF, SFSU, st. mary's, santa clara, etc...i go to the sfsu and it's actually quite affordable for in-state residents, though going up every year (UGH) but yeah, education is highly valued and it's readily available.
-proximal to silicon valley for jobs, though obviously there's the financial district in s.f., and we have a decent economy. i don't think we have crazy unemployment either, and finding a job would probably be pretty easy.
-it's relatively safe. oakland has a high crime rate, but not in all parts. and most of the city is pretty safe, too. all surrounding areas are mostly suburban and would be appropriate for child-raising.
cons
-it's damn expensive and if you're not used to paying $2000+ on rent for like a studio (this is more in the city, it's cheaper by like $500-$700 in the other surrounding cities), then this will be a pain in the ass. higher cost of living though luckily means more pay though, and i think minimum wage is like $10 or something near...highest nat'l average, i think
-BAD drivers. seriously. it's true, we drive horribly, but the good thing about driving in nor cal is traffic is nowhere nearly as bad as so cal, where you'll be in traffic for an hour like every day, just running errands.
i swear i'm on a tangent but can't remember what else i was gonna say...but i love the bay area, obviously!