Where do you want to live? I turned down a major Asian carrier for an Australian regional purely for lifestyle reasons. You get to a point where you don't really give a sh!t about what you fly, but rather the lifestyle and conditions that go with it.
I'm very glad I made the decision I did in hindsight. I find myself getting bored on the longer regional sectors as the pilot flying. I couldn't imagine how batsh!t boring it would be for 12 hours or so as an SO.
Just my two cents.