NW elites seem generally happiest with our domestic upgrade situation. The int'l upgrade situation is another story (it sucks). There are also no nonstops to Ohio or the West Coast from WAS on NW metal, but that's an excuse to earn more miles, right?

NW and CO elites both get unlimited free upgrades on all NW or CO metal flights that have available FC. Availability is much tighter on CO metal, though. And while CO offers nonstops from IAD to CLE, the route is entirely covered by all-Y ERJs.

I've heard pretty postive things about HP's and US's upgrade programs, too, but am not familiar with the details either.