Paying off mortgage early or reinvesting in other ways

[Jeff Libby]

I have been wondering what would be a better strategy, making two extra mortgage payments/ year or using that money elsewhere. 

I'm going to use a basic mortgage calculator for the doing the math on this example.

If I have a 200k house with a 165k loan amount and 3.75% interest, and .5% tax the monthly payments are roughly 850 for 30 years. If I paid bi weekly instead of monthly I would save 16k in interest over the 30 years but I would be paying an extra 1700/ year which could possibly go somewhere else instead. The mortgage would be paid off in 26 years instead of 30, so after the 30 years I would have a paid off house and approximately accumulated about 36k from rents since it doesnt have to go toward a mortgage payment.

Now lets say I invest that 1700/ year somewhere with minimal risk, growing at 7%. After 30 years I would have put 50k into it but it would compound to 170k, making me 120k profits on it. After 30 years in this scenario, i would have paid off the house, but accumulated 170k (minus taxes)

It seems that it would make more sense to invest the 1700 instead of using it to pay off the mortgage early but I'm sure I am missing a lot of variables so I want to get input from you smart people.