$4000 a month cash flow, only debt is 300k mortgage

[Brandon Aylesworth]

By this July, only a 300k mortgage is left for “debt”...no loans, cc’s, etc...all gone. Will have 4K a month cash flow after regular life bills are paid (food,etc).

What is the best thing to do with that 4K cash flow?.....throw on mortgage, save? Save then invest? Maximize 401k? A big part of me wants to hammer the mortgage, but I suck at delayed gratification