I don't think one is far superior to the others. Some definitely have some competitve advantages over the others.
United has E+ in coach, p.s. service SFO/LAX-JFK, and Channel 9.
AA has the best award redemption of the majors and international F to Hawaii.
CO/DL/NW/US have space available upgrades for all elite levels--highest first.
There are pros & cons to each program.