When transactions aren't going smoothly right before closing, it is easy for one or more of the people involved to become emotionally charged and react in ways that either anger or embarrass one or more of the others involved and can be inappropriate or unprofessional.

Tenant sent numerous inappropriate correspondence, involved other roommates unnecessarily and told us no repairs can be done during Tenancy, after we caught water damage to the brand new bathroom that was installed.

It also depends on your usage.

Because I am a software developer, I have only ever used it in the API context (write a script and pay for the limited API usage).

How can I charge my tenants for electric and water usage when it's all on one meter?

There is no way to fairly bill usage back to tenants as its not separately metered.

Nothing would be a deal breaker alone, but factor this level of expertise in when evaluating the complete picture.For example, a big problem that I've seen is if a single tenant building is applying with a regular lender, sometimes they apply a vacancy to their own DSCR (Debt Service Coverage Ratio), and they apply a vacancy factor for a single tenant building, which is just wildly inappropriate.

There can be fees for recreational facility usage, or additional parking spaces, or storage rooms.

Essentially when your property isn't sub-metered for water and the cost to do so is prohibitive, RUBS allocates the water usage based on the actual water bill to each tenant. 

@Kevin Griswold Generally, commercial zoning allows residential usage but residential does NOT allow commercial usage.