To me, the first and most important factor is the size and shape of the parcel in question.

That way you kind of hedge your bets (aka Risk/Reward).Self Storage is historically Recession-Resistant as it has everything to do with Death, Divorce, Down-sizing, Dislocation, etc. - things that are prevalent in normal times and certainly, in not-so-normal-times, too.However, RV & Boat Storage is similar but different, in that approx 1 out of 10 folks in the USA rents a Self Storage Unit, and that is not the case with Boats & RV's; hence it being a much more niche strategy. 

Most residences are single-family homes under 1500 sqft, with generous lot sizes ranging from 7,000 sqft to 0.5 acres for some properties.Interestingly, despite ample space, vacant lots in this area remain undeveloped with no additional units added.

There's a variety of ways to get a deal in front of you (I'm mostly a flipper), but basically if it looks promising, I run custom comps queries and check the current & past $/sf of renovated/distressed product in that city or zipcode.Here's a chart on 90066 I generated from my tool under Market Stats > Sales Data > Specific Zip Code:- My above chart (more available) shows the Avg Renovated $/sf (High) over time in this Zip Code, something completely different than charts/providers based on Averages/Medians only, like every other platform (RedFin Below, https://www.redfin.com/news/data-center/):- Can't select smaller locations such as City or Zipcode for their $/sf data, so it's useless helping me underwrite/verify a deal.- Can set Zip Code for Median Sale Price data, but again it's the median/avg so it's useless helping me underwrite/verify a deal.Then if that looks decent, I'll run Sales Comps, and get a quick summary of some key metrics based on those comps.

Zoning in cities against certain property types and sizes, etc. 

First, the zoning rules vary widely from one town/city to another regarding set backs, minimum size of home you can place on a lot, etc.

Detroit looks interesting, for the entry investment size.

But like most things you are going to have a ton of beginners listening to someone who is just out to sell guru programs and one size does not fit all in every state.. but one they get a BP pod cast its off to the races.

I’d look into the condo docs once you get them but the age & size of this condo complex make me think those issues are unlikely in this case. 

Keep in mind that there's no one-size-fits-all answer, and it's okay to take the time to figure out what's best for you.