They don't factor in any amortization of the loan (I asked Listsource about this); if the loan was 10 years old, this number in their equation is going to be far off.  

Do a simple risk/reward equation and see what it says.  

Like @Justin Anderson said, it takes into account the worst performing and mismanaged units.Even worse is that it also uses outliers in the equation.

The equation is never cash flow = wealth OR appreciation = wealth. 

The equations are simple once you understand what Cap Rate, COC Return, etc. all mean,..

I have a 2 year lease so did not figure vacancy into the equation. 

To me you're leaving a lot of numbers out of the equation which would paint a clearer picture, but I'm a simpleton.For option 2.

Find that answer and manifest that answer onto your website.I have turned ranking #1 into a mathematical equation. 1 + 1 = 2 no matter how often you do it.These are all people that used that equation to rank.

What that simply equates to is that the barriers to entry here are higher, and I personally think that's a good thing. 

There is a general equation in contracting that the cost of a project is 1/3 materials , 1/3 overhead and 1/3 profit . generally speaking this is pretty close  .