@Kent Hall My RUBS is on a three-unit in a trendy part of town where I end up renting to mostly young professionals. The building only has one water heater, plus Duke Energy charges a $35 meter fee per month per meter, so I decided it would be easier and more cost effective to go down to one gas meter. I've also gone to even billing for that gas bill, so I send the tenants the same invoice 11 months of the year and the 12th month makes up for variance.
A RUBS is an added layer of complication to the landlord-tenant (or PM-tenant) relationship. I think that getting it put in place effectively will have more to do with who's managing and how well they communicate with the tenants than the neighborhood the property is in.
In my case, and in the case of almost every gas RUBS in the Cincy area, mine actually saves my tenants money when compared to them having to pay their own gas bill (that $35 meter fee gets split among units instead of $35 per unit). I make sure my tenants know that before I ask them to sign the RUBS agreement.
That said, some inherited tenants will be stubborn about you "changing the deal" on them. That, and I still don't think that multi-unit renters are going to be willing to pay for their water usage unless they're getting an uneven advantage on other terms of the lease.