It depends on a LOT of factors. Remember, first, that the Los Angeles area is HUGE. It stretches from Ventura in the north to the southern reaches of Orange County, and from Santa Monica east to Riverside. It's 75 miles across in any direction, and almost all of it is city. Cities in the LA area have no space between them - you literally cross the street and step from one city to another.
This means that there are a lot of different climates and cultures down there. You can literally go skiing and swimming in the same day during the right time of year. The Basin is bounded by beaches along the Pacific Ocean, mountains in the north, and deserts in the east. The beach areas are cool year-round, while the inland valleys are cold in winter and hot in summer.
The wind blows off the ocean, and it pushes LA's famous smog up into the valleys. This means that air quality varies a LOT depending on where you live. It's clear on the beaches, very smoggy in the valleys. This is most pronounced in summertime. In winter, the rains wash most of the smog out of the air.
Which brings us to something else that surprises a lot people when they go to LA: the weather. The song says "It never rains in Southern California." Don't you believe it. It rains, all right, but only from about September to March. During that season it might rain once or twice a week. But then it doesn't rain at all from about May through August. It almost never gets cold enough to snow, unless you're high up in the mountains.
People vary a lot in a small area. Watts and Bel-Air are only about 10 miles apart as the crow flies - 30 minutes by freeway. But they could practically be in different countries for all the similarities they share.
I lived in SoCal for 15 years before I moved up here to the Bay Area. Personally, I like it a lot better here. But some people love LA. I'd break it down like this:
PROS
- Energy: There's always something happening, somewhere in LA. You can't possibly be bored if you don't want to be. There's a deli in the Fairfax district (that's in Hollywood) called Cantor's that has to be seen to be believed. They're open all night and the 3AM crowd is worth going just to watch.
- Coolness: There's something inexpressible about driving by places that most people only hear about in movies. Mulholland Drive, Disneyland, Hollywood and Vine, Santa Monica Pier, Ventura Beach, etc.
- Diversity: Any culture you want to experience is available somewhere in LA.
- Culture and Education: Los Angeles is home to UCLA, Cal Tech, and USC, as well as dozens of small colleges. Libraries tend to be large and well-stocked. There are world famous theaters, operas, symphonies, restaurants, etc. In terms of things like bands, plays, etc., everyone who is anyone plays there at one point or another.
- Climate: If you like sun, then LA is for you. When I say the valleys are "cold," that's relative - it seldom frosts even in the dead of winter.
- Sophistication: being in such a melting pot makes most Angelenos very cosmopolitan and accepting.
CONS
- Climate: Unless you live on the beaches (which are very expensive), most of LA is cold in winter, hot in summer.
- Smog: It's as bad as you've heard. When I moved to LA I lived in a little suburb called Claremont, which is out at the end of one of those valleys I mentioned. The smog was so bad when I arrived in July that it wasn't until the rains came at the end of September that I realized there were mountains behind my house. I literally couldn't see them. True story.
- Sprawl: LA is just huge. You can't appreciate how big it is until you go there. It's easy to get lost. In fact most gas stations and bookstores sell a map book called a Thomas Guide. If you go to LA, GET ONE OF THESE. They are absolutely indispensable when you take a wrong turn and find yourself someplace you don't recognize.
- Traffic: Rush hour on the Santa Monica Freeway is insane. That's all I have to say.
- Shallowness: I'm not sure what else to call this. It's a little hard to describe. To some extent LA is superficial by nature. It's the home of the entertainment industry, and that colors the culture of the whole region. But also, LA is a sort of transitory experience. Many people who live there either just arrived or are about to leave. This means that the sense of being part of a place is hard to find there.
- Concrete: In a sense, LA is 75 miles of pavement in any direction. If you like the earth beneath your feet, that is a drawback.