Like I said, cap rate is really only used for commercial investing when a cap rate is essentially set in stone based on the type of investment.

NYC has a CAP on Property Taxes, especially for certain Residential Properties.

You also have a cap on your income. 

There are neighborhoods that push hard against it and there is a cap on the areas where the map shows it is allowed, but the cap isnt close to being met (around 60%) so the market is still open for investors and as the STR horror stories get dispelled, I believe that many other areas will become more STR friendly. 

There is a cap on interest accruals on tax sale overbids. 

I have a couple B-grade, multi-tenant commercial listings returning a cap rate in the high 7% range, which is a bit better than the multi-family or single-family rental returns of today's market.

We are using the VA loan and have a cap of $417K.  

There was fierce competition on the property, which is justified because the most conservative NOI is around $2850 giving it a CAP rate of 8.5% and a nice COC return around 10% - 16% depending on how expensive lawn/snow/water/common area utilities are for the year. 

My goals are conservative, Buy and Holds with a cap above 7%.  

My comments are based on your analysis on Bigger Pockets.I don't like 2 houses on one lot because it ultimately has to be sold that way (reducing the value) or try to sub divide.You claim a cap rate of less than 2% and less than your cost of money.