Analysis of pay-off vs. keep loans

[Shari Posey]

I've read dozens of pros and cons about paying off properties early compared to paying off in 30 years. I have felt paying off was mostly a benefit for peace of mind and saving on the interest. (Yes, I know the arguments deductions for interest, etc.) However, I heard Suze Ormon give another reason and I just want to verify the math before I get too excited...
We've got $2,160 cash flow minus all expenses per month.
Is it true we would have to have $675,000 at 5% interest in order to generate the same income and preserve the capital?
That compares to $475,000 in total we paid for the properties. (Well, we also had a few years of interest before paying them off which I have not included but should to be completely accurate.)
Am I missing something in this anaylsis?