If the interest rate are close, then you should pay off the primary. 

@Ryan Rabbitt Did you end up pulling the trigger? 

Someone with $10M in the bank in cash just needs to put a lot of money to work and time value and tax write off is more interesting to them than a hungry investor in their 20s that has never found a deal.Honestly, books are great, but they are about as "boiler plate" as you can get as I'm sure you're discovering.

I use all the rental cash flow to pay these loans off asap, then repeat.

Or just strangers off the street you met at a REI group? 

The combination of all the above puts me shoulders above majority of the investors.

My question would be is a 6 cap the going rate in the area for that building.

It takes getting off the road everyone else is driving (the MLS) and putting some work into it.

I have clients doing 1 a quarter thats about the slowest to others that will go on a mini tear and I will help them buy 5 or 6 over a 45 day period then they go to work.But generally my busy folks will do 15 to 30 plus a year..

If the market is tough, I reduce the rent rate over the full 12-month term.