I plan to manage the properties myself until it conflicts with my regular job.I would appreciate any advice on these markets to ensure success and connect with local investors.    

Sounds like you have a plan to consult with some brokers and expose it to the open market. 

The STR market here has become way more saturated and competitive especially in San Juan. 

I agree very market dependent. 

From there we identify properties that could have some potential and if you are interesting in diving deeper, 1) we do a thorough video walkthrough to give you a realistic look of the property, 2) we give a ballpark estimate of rehab costs (we do 40 a year with our GCs o we will get pretty close), 3) we talk through market rent with our property management team, ARV, and potential highest and best use.Ideally you find great investor agents who know their market really well and have a network of resources to provide you with enough confidence to take reasonable action. 

Good potential for appreciation/rent growth upside as well in the next 5-10 years in my opinion with the market still being one of the most affordable in the country.

What I do not control is the natural level of rents in any given market at any given time. 

Can you please share any information on properties or markets where you are that can help guide my search?

Here's BIG concerns:1) Tenant has been there for 25 years - that's a crazy amount of time2) Rent is 27% below market - why is he giving this tenant such a big break?

Hi David, take as much time as you need to learn the Nashville market.