This is now used as a airbnb/mid-term rental.

If your goal is financial freedom, which is a long-term goal, not so much.Financial freedom is a long-term proposition, not a one-time event.

I have three listings, 1. unit with a pool and hot tub, 2. unit with a hot tub, 3. both units together as a 12 sleeper.Gross monthly income (after booking channel fees) for the first unit over a 7 month period was $7309.Gross monthly income for both units over a 14 month period is $11,297 (after booking channel fees) As a long term rental the combined rent would be in the region of $5500.Is it possible to sell the property based on the income generated by the STR business or would the value always be based on bricks and mortar comps? 

Deciding whether to sell or keep renting really depends on your long-term goals.

I am looking into my STR options but from what I have learned this is a overflowing market in the area and the vacancy's are increasing so I may look into mid term and long term only.

I am interested in buying a long-term turnkey property in a nice area (I live in San Diego so this property would have to be out of state).

I think that strategy works best in higher areas or mid term rentals near major employers.  

I would like to find a way to generate additional income and am exploring options other than having a long-term roommate.

Cool part is that we did the exercise last month and have already been able to see traction on some of the short term goals. 

Most investors who take this route are not short-term investors and do not enter the investment with a timeline for sale.