The devaluation of mileage programs makes it difficult to stick with one airline. Last year I gave up on United and started flying Alaska almost exclusively. Alaska had a reasonable cary-on policy until recently (I travel with expensive equipment that I don't want to check). Today I'm looking at Delta credit card programs. 2018 will be a year that I use Airline partner credit cards and just shop for the most convenient flight times to my destination. Loyalty is not rewarded anymore.