For the OP’s unique situation the loan would be…
The OP experienced negative arb the personal debt YOC vs. expense of personal debt (4.75% versus 5.77%). Inside your instance there exists favorable arb (YOC vs. price of credit) considering that the loan are IO. Positive arb = high ROE, adverse arb = small ROE.
Should you be in a great deal and you will have bad arb you are actually generally gambling your home appreciation (through either revenues increases or cover rates compression) could make upward back having negative control during the hold time. Designers like for example get this solution regularly (they have got building financial obligation and zero earnings from your house during construction).
For the OP’s original illustration unless absolutely a value-add aspect of enlarge money, the home or property is not at all stable etc and/or OP try wagering on cover speed compression (scary) then your debts is way too high priced and it’s not likely much.