Based on the behavior of both sides (DL and US Bank) the sensible course would be not to use either the FlexPerks or Skymiles Amex cards. Both companies have been deceptive and treated the customer as the lowest priority. But in the short-term we will use both the FlexPerks card and DL Amex enough to get the bonuses. We may stick with the FlexPerks card longer as our spend will easily exceed the threshold for the annual fee waiver, and you at least get 1% cash back if the airline award thing doesn't make sense to use. But in the meantime I'll also be researching alternatives, including the Hilton card, the CO Presidential MC, and a card from someone like Capital One.