I'm a UA 1K and I've done the account linking bit, so now I'm a OnePass Platinum. And I know the general rule is to use my UA account when I fly UA metal and vice-versa. I haven't flown CO metal since linking, and I'm curious about peoples' experience. Am I more likely to be upgraded as a 1K flying UA metal, or as a Platinum flying CO metal? Today, my most common route is SEA-ORD/IAD-RDU, and on UA I'm probably upgraded 90 percent of the time, with the only misses when I change flights late in the game. If I'm flying SEA-EWR/IAH-RDU, should I expect a comparable hit ratio for upgrades? I've heard that CO likes to sell their upgrades before giving them to their elites, and so upgrades are harder to come by, but I have no idea whether this is true or not.