re: Pay $1,000 extra to house or invest?

Thank you guys for the advice. I do have a 401K and it is maxed as far as I am willing to go at the moment (company match, etc) I am still struggling with one thing in my thinking though. I get that I can build wealth with saving the $1K a month into something that compounds, but I don't get how freeing up that money per month would not help me after it is paid up. I freely admit that I am a per month type person. I look at finances and how much money I have to work with per month vs. long term. I simply cannot grasp how paying off the mortgage is not a good idea to consider with all of the other options as well. Is it strictly because paying off 120K towards a mortgage vs. investing the $120K and earning interest during 10 years that makes it better? Because in my mind I see that I can be mortgage free in 6 years and that would free up a tremendous amount of cash of future earnings. Yes it does leave me with nothing to show for it liquidity-wise, however, if I stay here long enough than won't that count? I am just trying to understand from a different perspective.