Yet another LAX flyer here. I generally maintain Plat or Gold on NW by flying 4-6 R/Ts to Europe. Lately, most of my earning has been on AF. It used to be almost all on KL. I fly NW when I can upgrade a B fare at a decent price. Domestically, I'll take NW when I can, unless I can go direct on Virgin America--I love them (so far...)