One downside I've heard about Sec 8s is this yearly inspection. 

But if you look at the data, you will see some cities have high projected appreciation with low downside. 

Certain areas of Texas and Philly are additionally ok, but heavy new supply, combined with much lower land values makes it more susceptible to the downside risk of home ownership.

In the case of high cap rates, it could easily hide the downsides of the areas they are looking at.

The downside to less back-and-forth negotiation is less negotiation.

The downsides in my opinion are less overall rent and the layout of these units seems designed for students with its square box layout with a bedroom/ bathroom in each corner and the living room/ kitchen in the middle I'm not sure many families would rent.

Script for the magazine: "excellent builder, long track record, good neighborhood, nice family homes for the community, and improving property values.." generic information on the build...no personal or background information needed...that stuff can be told elsewhere and has more downside risk (trumpeting limited experience to all parties involved) than upside benefit.

So the down side I was worried about - a lender counting my first mortgage against as part of my DTI ratio an not counting any of the rental income seem unfounded. 

@Patrick Allen, good points about the downside of a downturn, making purchases tough.

also would like to know the down sides about going with a new build. thanks!