Not paying off properties
We have two properties with mortgages. One (a rental) has a balance of $150k at 3.75% interest and the other property has a balance of $775k at 2.625%. We originally wanted to pay off these properties in a few years by saving aggressively and making extra payments but considering the low interest rates, we are now thinking we put the extra funds towards an investment account. Our first goal is put all surplus savings for the next 16 months into a investment account and once the balance surpasses the mortgage balance on the rental, we move towards contributing to a new investment account and do that for several years until our balance exceeds the remaining mortgage in the other house. We plan to just invest in SP500 but even after we save enough to pay off the mortgages, we will not playoff the loan early and just keep making monthly payments until maturity (in 20 and 24 years). Is this a sound plan or is there a point where we should just payoff the loans early? I guess we want to aggressively save and have the safety cushion of not having to worry about the mortgage for decades but we also don’t want to actually pay it off and forsake likely higher gains through investing. Are we thinking about this the right way or at we missing something?