Great thread!
This week, $3600 on tickets to China, in Turkish Airlines' "Economy Comfort" class. Last year, this would have been on UA in E+ -- which, by all accounts, pales in comparison to the TK version, which is more like UA's domestic first. Yet, the total cost of a regular economy ticket on UA plus access to E+ approaches the TK "Comfort" cost. Since I don't get free access to E+ at booking anymore, staying loyal to UA in this case would result in almost zero net benefit (just the 25% RDM bonus and two pairs of banged-up knees).
Last week, about $300 for Amtrak Acela tickets to the DC area. Last year, for a similar trip, I flew.
A few weeks ago, about $600 for HPN-Dallas and back on US. Last year, that would have been on UA.
And before that, a Z fare on LX to ZRH. Last year I would have gone out of my way to fly this on UA.