Specifically:What square footage ranges are performing best?

I assume you're buying SFs in the 1200-1500 SF range and doing some light to moderate rehab, is that right? 

Maintenance and repairs typically range from 5-7% of rental income, compared to the standard 10%, as new builds have fewer immediate issues.

For the most part the homes have been under $225,000 renting between $1495 - $1695 range. 

Within that area what does your demographic research tell you about the age range? 

I've sold dozens of homes during the so-called Eligible Date Range, but figure any payout will be peanuts after all the lawyers get their take from the top. 

also noting most people arent' aware but the credit score run by a mortgage lender and say a general lender like a bank are actually going to be different scores (and likely slightly different ranges) - with some greater weights on mortgage debt for the mortgage lender Credit Bureau settings

This can range from a few thousand to several hundred thousand dollars, depending on the complexity and size of the project

My brother in law works for them, absolutely loves his job and his employer, so very hard to be objective about deciding to invest. 

The objective is to upsell to a master mind program or the artificial intelligence datasets, which also have zero response rate.