I'll echo other Los Angelenos' assessment of LA. I live in Downtown LA, a few miles from USC.
For me, LA is defined by its weather and urban scrawl. LA has unbeatable weather (it's high 70s in my area today). I think we've had maybe a week's worth of rain all season, but I will also say that we're going through a serious drought and a state of emergency has been called -- depending on how much rain we get in 2014, this may become an issue.
The urban scrawl lends itself to a a few positive things: 1) Numerous developed/developing neighborhoods with their own unique cultures; 2) Possibly the best food in the US due to the diversity and size of ethnic/racial communities and neighborhoods; and 3) You can also find SO many things to do every single weekend if not day -- from music festivals in parks, outdoor movie screenings, art exhibits/art walks, film festivals, museums, camping, hiking, shopping, etc.
On the other hand, urban scrawl also has made it difficult for LA to develop a sensible public transportation system and avoid heavy bumper-to-bumper traffic. I have never liked driving, so I tried to rely on our public transportation system my first year in LA and was exhausted by it. We have multiple expansive bus systems as well as an underground/above ground metro system. For the former, they're often off schedule due to the traffic and are consequently slow. The metro system is great, but services few neighborhoods. Like jhzu said, specific neighborhoods in LA are very walkable (downtown, Santa Monica, West Hollywood, Koreatown, Culver City, to name a few). It just becomes nightmarish when you have to venture outside of your neighborhood, especially during traffic hour.
If you do decide to come, I'd be happy to offer you some advice on which areas to check out! I like moving, so have researched/looked at housing all over LA and have lived in multiple neighborhoods.