Your primary has an incredibly low interest rate, and your rental (I hope) is getting positive CF, which means your tenant is paying it off for you. 

I specialize in single family rental properties in the Huntsville area and this area has a proven track record of increasing home values.

Quote from @Drew Clayton: I need advice on how to handle the transition my long-term rentals to a new property manager when my current one won't return calls, emails, or texts. 

If so, I'm actually insuring two rental properties with them.

But to answer your question why you still see so many active STR's on Airbnb in a restricted area, it could be a couple things: It could be a "hosted rental" meaning the homeowner is there and is just renting rooms on Airbnb.

Maybe lease a mid term rental and rent out your unit, then look to buy another place.

Does anyone own rental properties in Detroit?

Feel free to inquire about their staff qualifications if it's a larger organization.2.

After 12 years in the furnished rental game, I'd say that is a pretty good sample size. 

Quote from @Erica Dike: If your vacation rental is designed for everyone, it speaks to no one.