The key to Hagerstown is accepting whatever vacancy numbers the market may throw at you until you find a QUALIFIED tenant (i.e. one that hasn't already been through the eviction process).
When our screening was weak we returned 0-4%. Over the past 12 months with stronger screening we're seeing 12-15% return. This is with sometimes leaving a unit vacant half a year if that's what it takes to find a tenant with a clean background. Getting access to the CoreLogic eviction database was key for us. Evictions are not on CaseSearch but this company sends reps into all the Maryland courts each week. The search is $8 and has turned around our returns in this tough market.
Everything said above about the city is true. Only they don't crack down on slumlords. They crack down on the compliant landlords they can harass to comply with various minutiae and get their numbers up. Some 70% of the properties downtown have never had a code inspector visit. That tells you everything you need to know about their motivation and "mission." Also expect your property value to decline each year and your property taxes to go up each year. It's the second highest tax jurisdiction in the state now.
I consider Hagerstown a mistake. We get the same returns in Frederick with less than half the effort.