@Troy Fisher is spot on about the HOA 4-plex issue. Your damned if you do and damned if you don't. The cluster zoning that most small multi building are in have created pockets of blight though out the city. After managing them for ourselves and clients over 25 years, I can state the biggest challenge of not having an HOA. You may have the nicest building on the block but it doesn't matter if the owner next to you chooses to slum the building, allow cars on blocks in the parking area, allows 4 dogs per unit and doesn't screen tenants. How can you get and keep good long term tenants when you do everything correct and the owners around you don't? And it may not be that way when you purchase but can change with time quickly. Then what do you do?
If you have the HOA as Troy stated, you loose control over fixed expenses to the governing board but you eliminate the bad owner issues.
Small investors don't have many options. Focus Group has two large apt complexes(over 200 units) under construction and Picerne Dev already offered to buy them at a 5.5 CAP. So the newer product being built takes deep pockets.
You asked about areas. These issues are city wide. The only real "change" is happening downtown as the area regentrifies. Downtown projects may 2016 will give you a snap shot of the current downtown projects. Decent, rehabbed Multi family is desperately needed in the area to sustain the workers that want to live in the area and not pay $1500/month in a tower rental. There are at least 10 restaurants and urban lounges gearing for opening in the next 6-9 months because of the success of those in the area are having that took a chance on the revitalization early on. Makers and Finders and HopNutz in the 18b Arts District are flourishing. Their employees want to live in the area and are unable to find reasonable housing.