A bird in the hand is worth two in the bush.

Taking CPP is cash in the pocket.  And likewise a dollar in the pocket, is worth two in future CPP benefits.

Yes if you live to a ripe old age, deferring is the way to go from a strictly financial perspective.  However I don't agree with this for two reasons.  

The first is no one can tell me how long I will live, so while deferring taking CPP may make sense, there is a definite possibility I will leave less money to my spouse and/or kids.  CPP spousal amounts are not very well funded, and there is no sum accrued to kids on death, so if both me and the Mrs. kick early the kids get nothing.  Spending RRIF money which is mine, means it is gone and out of the equation.

The second is that I simply like to be in control of my own finances.  If I don't require CPP, I can save it and earn income on those savings. So I plan on taking CPP at 60, yes early.  I may end up with less, but I will not end up leaving a bunch of money in the bush.