To say they're "high maintenance" would not do it justice. 

There are opportunities, but due to bureaucracy, the slow pace of courts regarding evictions, laws that protects tenants too much, and the general feeling that the government can pull the rug under your feet at any moment, one has to be careful.The problem with Spain is not about people's mindset, or lack of skills.. it is more about months that may become years (incredibly slow), and lack of confidence in courts or justice in general.

Cash on cash or even cap rate doesn't do the returns justice.

@Scott Smith right, I just take a very Maugham very of Pollyannish behavior, especially among ostensibly professional landlords.With our increasing political and capricious justice system there seems like even more cause to worry; more now than in the past, of being successfully sued.

It’s no longer about “justice” but redistributing your wealth from the ‘haves’ to the have not’s.

Anyways, as you can see, there are so many little details and nuance that to make a blanket answer that airbnb arbitrage is good or bad doesn't do the OP any justice as it all depends on the specific deal's details.Oh and to those who say that STR are a lot of work, at least in my experience, buying either a single family house, condo or apartment that isn't more than a million dollars will have a lot of difficulty attracting a GREAT property manager. 

You go to the justice center on a weekday and they start the bid 70% below what the house was worth.

Especially when one is trying to escape the US justice system.

Always invest for cash flow, then appreciation is just icing on the cake..

You won't be able to do anyone justice trying to figure out commercial wholesaling on the fly.