If you have the Amex gold reward to earn 2x points, that's obviously better than the 1.5x on the infinite visa.
It also depends on your redemption strategy. If not redeeming for luxury J/F tickets but only for Y tickets, an AE mile is worth about 1 - 1.2 c. So the mbna 2% back cards work out better than the 1.5x points.
I also got the cibc infinite visa, because of the bonus points, and also the 1st year fee waiver. Next year at renewal time, we'll see if they offer something good to keep me as a customer. If not, there are still many other good point card around.