What Nash says is really spot on. My SWA buddies put in a lot more time away from home than I do, and have both told me they'd trade working conditions with me in a heartbeat. One quick example, is how I can turn one week of vacation into 4 weeks off.
Trust me, passenger flying gets old after a while--and I've done my share of it. Quality of life, however, never gets old. I'd pick cargo.