Love the "stack" method. 

I toured it today and am seriously considering putting an offer in bc the house is turnkey and in great condition but I have one concern.

I am interested in pursuing the BRRRR method, but I am hesitant to take this on due to the "Rehab" portion of the strategy. 

Can someone state what some of the most important pros and cons are for getting into this investment method. 

Air conditioning in June and July in Birmingham is a significant issue, and heating and cooling concerns are always a quality of life concern for our company, especially during the hottest and coldest times of the year.

How to, or even whether to finance, or refinance, needs more details to answer including ARV and, calculated by dividing the net operating income (NOI) by the total debt service, the projected income and expenses to determine the Debt Service Coverage Ratio (DSCR).Typically 1.25 or better, it's possible to get it done with lower, depending on other factors that include the operator's three C's of credit: Capacity, Collateral (think location, location, location), and Character.Given a clearer picture of these and other factors, the Buy, Rehab, Rent, Refinance, Repeat (BRRR) method is another option.

I’m planning to use the BRRRR method in the Upstate New York region.

Is this method a commonly used method by investors?

Mix in the improper repairs I would be concerned. 

That's a primary concern - how much cash you can generate to purchase your MF.