1K free agent here:
I fly WN now when possible. They status matched me to A list, I get more frequent departures, similar pitch and with no middle seats, everyone is in first class. Also, the differences in employee morale really show. DL is also getting a share of my business.
When do I fly UA? Only when no OAL serves the route (after all, I'm still technically hubbed in at ORD). Also, I bought some $180 R/T fares ORD-SFO that I intend to upgrade.