@Sarah J.Ben's three questions are good - disregarding the fact he is coining new words ("amenetized") again.Take a good look at both neighbourhoods to see if there is an obvious explanation for the school rankings:- is there a social-economic difference in the population?  

The property is in a sparsely populated area, but it’s halfway between a city of 300k and a popular resort town (boating).I think I’m looking at a solid opportunity, but I’m new to self-storage.

I'm from Iowa, so I don't know anything about New York co-ops, but I thought it was easy to sell real estate in those high population cities.

Which adds another 60,000+ fully employed people to the area population. 

Assuming this is a class B or C property (can't imagine a property in a nice area would cashflow like that), I'd hold onto it for the cashflow so long as the neighborhood wasn't depreciating or there was a net population outflow.

Especially if the house is not in a densely populated area.

KWC and Halifax ranked the second highest population growth rate in Canada (according to a dailyhive article). 

The larger the surrounding population, the lower the cap.  

There was negative population growth of the city of about 2% in 2017.

Is there anyone here that can tell me about the Zephyrhills market for buy and hold strategy as far as jobs, schools, things to do, renter population. does it make sense there?