However, he will shy away from the 150-units deals because he says he is no interest in becoming the next big developer/investor with 100 employees and offices across the country.I bring this point up to highlight that some of us have an intrinsic style of investing and don't see investments the same way regardless of mathematical conclusions. 

If you reinvest at 3% or greater you’re always better off keeping the low interest loan as long as possible.The reason people believe these strategies that defy mathematical analysis is 1.

In general, if there are multiple mortgage loan inquiries within 30 days, FICO formula will aggregate these inquiries as one inquiry, because the mathematical model knows you are rate shopping.How does the model know this? 

The mathematical equilibrium.

If the Fed pushed overnight rates to zero and nominal 10 year rates went negative it would mean the deflationary environment is accelerating - which mathematically would mean "real" rates are rising and the risk premium on loans would spike.

If we find assets again in a range that makes sense mathematically, we'll go back in.

Mathematically speaking all of the limited partner's outside basis (80% interest) would have to be multiplied by .63 to compress to 50%.

Your number comes to 3 months' vacancy at a mathematical average of all rents.  

@Brian Volland- the statement about ROI on paying down any debt early was just a general statement of mathematical fact. 

Mathematically, I could be entirely wrong.