回复：why?

let's say 100K (free and clear) of property that has the return of 10%.(your profit is 10K yearly)

If you borrow 80K at 6.5%, you pay 532 a month, 6384 a year, your new profit will be 10K-6384 = 3616. your return then should be 3616/20K= 18%.

rough calculation shows that your return is much higher if you borrow.

result shows that it does not pay to pay more equity.

If your return rate is less than 6.5% (it would make sense to pay down principle in this case), the borrowing rate, you should not invest then. it is not worth the risk...