No wonder new investors get confused. I tend to use COC vs is ROI is an evaluation tool.
All of these types of metrics are tools, used for specific analytic purposes. There is no 'one is better than the other'. That's like saying, "I only use 1-1/2" nails. All other nails are wrong, so I never use those other nails. Or screws. Or rivets."
I personally use all of the following:
COC Cash on Cash
ROI Return on Investment
ROE Return on Equity (specific investment)
RONW Return on Net Worth (am I growing my wealth?)
NOI Net Operating Income
DSCR Debt Service Coverage Ratio
DE Ratio Debt to Equity Ratio.
Scenario comparing use of COC vs ROI to evaluate performance of a potential investment:
100,000 property purchased using Cash
100,000 cash purchase.
$12k per year in cash-flow
COC 12000/100,000=12% COC
ROI 12000/100,000=12% ROI
100,000 property purchased using leverage (debt).
20,000 down, 80,000 financed. (400/mo payment)
$7200 per year in cash-flow
ROI 7200/100,000= 7.2% ROI
COC 7,200/20,000=36% COC/CCR
Why does this matter? If I have $100,000 to invest, I can buy one property for cash and make $12,000 of cash flow per year.
Or I can buy 5 properties using debt making 5 x $7200 per property. That is $36,000 per year on the same $100,000.
This example shows why we get greater COC returns when we leverage a property, while ROI tends to decline, due to carrying costs (interest). We also increase certain risks.
I hope this helps!