Service wise it's SQ >> OZ >> UA >> CA. I don't know about OZ and SQ hard product on these routes, but UA beats CA hands down, even if you're on the 350 on CA.
You might also have MU and CZ as options. Between the big three, CZ >> CA >> MU in my humble opinion on soft product. Not sure about the hard product on these routes.
BTW. UA will start flying to LAX soon as well.