This is more like buying a car with a big trade in AND financing it.

Realize the trades (plumbers, HVAC, electricians) are expensive.  

Some might be cryptic when it comes to openly spilling trade secrets but New York where it seems you are located is a major financial center.

Next they will be refinancing these out and these properties will re-trade again when the next shoe drops.

Think E*Trade or Fidelity with different paperwork.

Supposedly, rental properties hold their value and vacancy is low during downturns because of people trading down to rent, etc. 

The market in which the buyers are foreigners or well-to-do Mexicans and property are traded in USD and which are in specific (types of) locations.B.

I grew up in the handyman trade so i can do the work, just don’t know the financial side.  

Pay a property manager to swing by the property every so often and send me pictures?

In summary, the trade off for lower cash flow can be a group that operates more conservatively with a low LTV ratio, ample cash reserves per door, underwriting to rising cap rates, and 40%+ of return deriving from NOI, all of which will mitigate the effect of a downturn on your total return.