Caterina's place in Highland Park was the quietest, calmest Air B'n'B I have ever stayed in, and I say that with it being in the center of Los Angeles. Just a wonderful almost-studio-apartment, with a huge shower with incredible water pressure!
I slept with the windows open for the first 2 nights I stayed - that's how safe it feels there. The neighborhood around the house is exceedingly pleasant as well. I walked to the "Super-A" grocery store one day, supposedly a half-mile away, but it felt closer.
Caterina was actually out of town while I was there, but her husband Ciro was a wonderful host, and extremely helpful - going so far as to loan me some sunscreen one day when I was rushing out and realized I wouldn't be able to pick some up.
I can't recommend their place enough - if you want a pleasant, long-term stay in LA, this is the one for you!