Caveat is that turnkeys sell for the high-end of market value, so disposal in the first few years will likely lose moneyCONSSpecific market and asset risk is long-term (per property - mitigate by diversifying across different markets and property types)Spreading risk across multiple assets and markets requires multiple investments and quite a bit of due diligenceTurnkey properties (along with most other single-family homes) are becoming harder to acquire and thus more expensive, compressing returns and making it harder to find properties to buy with solid cashflowPortfolio risk from individual units is high (until sufficient number of doors achieved to mitigate this risk)Using leverage requires qualifying with personal credit - may become harder/more expensive with recently-announced changes at Fannie MayRequires some effort (to "manage the property manager") and decisions required at some point for capital expendituresQUESTIONSWhat unique risks are there with the turnkey single-family rental model?

I could have hired a PM, and I'd still spend that same amount of time cashing checks -- except the checks would be smaller.If you are able to do everything a PM would do for you, and your quantity of work and time is reasonable, why wouldn't you invest that time in saving that money?

Quantity isn't a good thing. 

However, at some point I dropped tax liens and associated investment from my portfolio because (1) the vastly different nature of the investments depending on state and even municipality (2) the crazy amount of competition resultant from the publicity being generated (3) the decreased ROI of available tax certificates (4) the time required to research what could turn out to be a relatively small sum invested and (5) superior returns available in our other investments.I came to the conclusion that tax lien/certificate investing can be very profitable IF the investor gained intimate knowledge of the procedures in a particular state AND gained knowledge of property valuations in that geographical area AND had sufficient capital to invest to make all the “legwork” worthwhile.  

However, with a recent rule change, the county areas were capped (maximum permissible licenses) many of which will be reduced by half of the present quantity and assumedly this will increase the productivity of the remaining active rentals. 

We do have a sufficient emergency fund.

You'd expect they have the sufficient flood insurance to cover the damage and rebuild whatever needs to be rebuilt/fixed.

If they can observe traffic coming in and out of the house, they will make a larger quantity arrest and will build a great relationship with yourself and the PD.

Simply showing that the 50% rule of thumb is one way to reduce the risk of a negative cash flow investment is sufficient.

In the past I've just taken a screenshot on my computer screen of my bank account balance and that has been sufficient for even one of the big 5 banks on a short sale.