Mastercard is a tough sell for many (myself for one) with Costco not taking it. I suppose as a family man (yes, I'm the guy hauling 20# tubs of mayo out of Costco regularly) I may be in the minority but I just don't have ANY use for a Mastercard.
I love the 1.5X kicker when using the Chase travel portal (basically Expedia) and roll over points from my Chase Freedom Business card (5X on telecommunication, 2X on gas). My usage works for these rewards and I think that's the thing with all these cards. You just have to read all the offers and find out what works best for you.