I'm based out of LAX. I prefer DL's service to JFK, my primary destination, but UA and *A partners have more international routes out of LAX. So it's more or less a wash to me which airline I want to go with as my primary choice. I'm currently Silver on DL and Premier on UA, but I want to drop one airline and focus exclusively on the other to build up better elite perks.

So...anyone have strong opinions on whether I should hitch my wagon to DL or UA? Thanks.