It has been a blessing to me as it is difficult to find a reliable handyman and I am not much of a do-it-yourselfer AND they charge one fee for both units.On the down side, sometimes they have shoddy repair companies.  

Permits are very difficult to obtain (we build homes in Chicago, so that may be a non-issue for us considering what we have to deal with here LOL :)4.

Finding good property management is difficult, especially when you can't keep close tabs on them. 

Although its difficult to not take action when you feel deceived, I would vent this to friends, punch a pillow, or maybe knock on their door and run away. 

Then you can start collections on that judgement but that is highly unsuccessful, difficult and generally a waste of time and money on most people. 

However, that is very difficult to prove.

It is always difficult to go back to the seller once you have an agreed upon sale to discuss previously unseen and unknown issues on the property which may need some concession or seller to address.

It would be a little hard to get out of, but not more difficult than a retirement account while providing more freedom and current tax and income benefits.Shoot me down, please.Thanks in advance,Jonathan

Push credit and debit card payments hard, to make life easier for you (auto-payments), and make cash payments very difficult to do and/or not accepted (eg no office onsite, etc).

@Dominick Galinis specific but narrow point - it's much more difficult to BRRRR if you use conventional financing and put 20% down on the purchase.