As a native southern CA, I agree with you that LAX is a headache! I generally try to avoid it, esp with traffic. I usually take ONT (Ontario), but my folks started to move away from that area. Burbank is a very interesting airport that has no bridge(?) to the airplane. It's a breeze because it's small. It cannot be expanded due to limited space.
I believe those "bridges" to the planes are called jetways, but yeah, Burbank doesn't have 'em. Neither does Air Force 1. You walk out on the tarmac and climb a mobile staircase affair to board. It really makes boarding faster because they can board from front and rear doors simultaneously. In the case of the DC-9 family of jets the rear door is a ladder-like stairs contraption that drops out of the tail. Same with Boeing 727s (rare these days), on which the rear door is sometimes known as the "D.B. Cooper door."
It's my understanding that the nonexpansion of Burbank is due more to ferocious political opposition than a lack of space. Just to get the OK for a remodel of the terminal the airport authorities had to promise not to try to expand for a number of years. That's fine with me - I like it the way it is.
Never been to Ontario; or Palmdale, for that matter.