Join Date: May 2004
Location: formerly Gold now Diamond, formerly MSY, now LAX, formerly NW, now DL
Programs: Hyatt Plat, Hilton Gold, SPG Gold, Delta Diamond/1MM
Posts: 4,736
Northwest Is Best
NW is best for free unlimited US domestic uplgrades for it's Elite. I have been Gold for the past 3 years and Silver the year before that and have only sat in coach on domestic flights a very few times on NW. My success rate is about 90-95% on usually very discounted tickets. On CO, the success is much less maybe 50% if I'm lucky.
Of course for international upgrades, there are none for free for Elites officially.