Adam,I hear that statment a lot but the key component of this REI game is once you have your mortgage paid down. 

.- Uses no or very, very little fund leverage (LOC for less than 20% of fund equity) This is very important component to realize and understand - where are you in the debt stack- Lends in one specific location/region that fund managers have deep operational experience in and which has speedy foreclosure laws.

Make a list of all assets and their components (how many roofs, refrigerators, heating systems, etc?)

First, there a number of investment thesis' carried out by syndicators with unexpected headwinds, not solely betting on rates.  

Plus, it's one of the key components to a successful STR! 

It's a budget friendly option to some of the other services, and they have engineers on staff + audit defense, but the more expensive cost seg companies ($1500-2500) will actually do walkthroughs of your property via Facetime to more granularly estimate components of your structure. 

What were unexpected things? 

As Jaron stated you will need to plan for the unexpected, such as vacancies and repairs.

You never know how fast regulations can change, and if you have multiple exit strategies you mitigate a lot of unexpected risk. 

The reason I am selling the Condo is to pay off some personal, and unexpected debts of about $18,000 to decrease my DTI to help me qualify for my Dads VA loan (they want to move to Texas), which is a 3BD 2BA single family home.