For me, none of these variables looked favorably for the smokie investors buying at $500/sq ft. 

Don't be afraid of higher rates, it is just one variable.

Also MTR pricing software might not be effective yet because there are so many variables with properties its hard to truly comp and get an apples to apples comparison (without looking further into the property and the amenities that are covered)For example the pricing software will not know exactly which utilities are covered, how nice the furniture is, term of lease which can impact the rate, other amenities that is not uniform amongst MTR inventory.I recommend manually finding comps on Zillow.

This model would factor in dozens of variables from traditional and non traditional data sources. 

I know enough to know that there are so many unknown variables out there when it comes to investing in stocks that I've decided to just side with the very convincing and the strongly defended academic theories of guys like John Bogle, founder of Vanguard.Real estate is still an area I'm trying to learn as much about as possible before making any long term commitments that impact my finances and lifestyle.  

Rates will be comparable to an investment HELOC (likely slightly lower) but are fixed, not variable.

I'm not interested in paying off cheap money with interest only variable rate debt. 

There are a lot of variables involved here.Min down payment requirement to meet min DSCR would most likely be 25%Whats your estimated credit score?

My knowledge is limited and there are obviously variables in location, size of units, amenities, expenses, TI, etc.

There are too many variables related to you and your lendability to give a solid answer on this.