"NY BIGLAW makes me want to vomit"
You will be sorely disappointed if you expect LA, DC, Chicago or any other BIGLAW for that matter to be notably different from NY BIGLAW.
I interviewed in LA, DC, Boston and NY. A firm will pretty much buy any rational reason for your desire to work in one of these markets (I cannot speak for Chicago). I lived in New England for a few years (15 years ago) and told Boston firms that I wanted to return. I went to college in the West (not CA) and told California firms that I preferred the western lifestyle. Finally, I told DC firms that I was interested in politics and government. I wasn't lying. All of these things are true, albeit somewhat exaggerated for persuasive effect.