If one or more units are vacant, the remaining units often don’t provide enough cash flow to cover expenses, making it harder to meet operating costs.Maintenance costs: A fourplex comes with four times the appliances, plumbing, HVAC systems, and other components to maintain, leading to significantly higher repair and maintenance expenses than single-family homes.If you want to see the detailed calculation, read this BP blog - More Units Doesn’t Mean More Money—Why a Single-Family Home Can Beat a Fourplex.Resale value: Multi-family properties have a limited buyer pool—mainly investors—who base their offers on CAP rates.

He took a 401(k) loan to fund the down payment on a four-unit building in a rapidly appreciating neighborhood.

Ask how many units they manage and how much experience they have.

How do you advertise your vacant units?

Ask how many units they manage and how much experience they have.

Ask them how many customers they have and how many own a single property vs. many units.

Sometimes the tenants are coming from shelters or other communal type of housing where maintaining a space my not be solely there responsibility so maintaining the unit may not be to your liking. 

I have tons of my units leased by people who do airbnb.  

I have bought a couple of units and now working on my own development.

No east ,   @Bob Stevens thanks, I have a vacant 2 bedroom unit I'm about to list on the east side.