I was just thinking that Barclay's A+ actually gives back 2.1% per dollar spent and can be used on ANY airline and more...
One can EARN more than 1 MR per $ spent, starting with 1.5 MR per $ on Everyday Preferred (or 4.5 with same card at groceries) or as high as 10 points per $ on restaurant spend (special promo) on the Blue for Business. The BP doubles the REDEMPTION value, so you get more than 2.1% per $ spent.