As someone who's never invested in real estate before Puerto Rico is a very difficult place to start, since of how minimal public data is. 

Privacy Shield, has made it difficult for companies, including real estate firms, to transfer data across borders without risking compliance violations.

@Raghul Manoharan what's so difficult with the NARPM Calculator?

Also, in Chicago I see it being quite difficult to even find landlords that would be willing to allow an arbitrage situation.  

I do agree some rents versus house prices can be difficult, but being creative is key...

That's unusual and it would be very difficult to find a passive investment like that.Also direct control means I know exactly what's going on.

I have a former post and the lady has been super difficult to deal with for the simplest of things.

go to her broker, make it super difficult to work with. go after her license, go after everything and say all you want is a release. you are a consumer. the law is pretty clear. look up procuring cause. buy a different floorplan of the same house int he same neighborhood without those addresses and you'll get around it 

I'm an investor in NJ, mostly in North Jersey but very difficult to grab multi families, anywhere south of Monmouth county there is more inventory and have a better chance of landing something that makes sense. 

I suspect they were talking about difficult turnovers with problematic renters, bigger repairs, heavy cleaning, maybe some missing rent, and longer vacancies.