Bro, different strokes for different people ...
In today's climate of low mortgage rate
Scenario 1 - non savvy investor
Keep money in CPF to earn the 2.5%...
Use cash to pay monthly installment....
Mortgage rate is only 1.x%... still lower than cpf....
Better choice
Scenario 2 - savvy investor
Use cpf to pay monthly installment...
use cash whereby you can get returns exceeding 2.5%...
if your cash can only generate 3%, you make net - 0.5%.. Of course with cash, you can dabble into many other instruments... which CPF you cannot... hahahaha
in scenario 1, you make net>1%...
So really depends...
Me, i prefer to keep my money in cpf and use cash... but saying all that, make sure you have enough cash stashed away for emergency... hahahahaha