I have been using TrueSubmeter now for 4 months and I am very happy with the service (customer service is an entirely different issue). Due to finding quest piping inside my triplex during the remodeling of one of the units, I elected to repipe and separate all the units. The city would not provide separate mains, as a result, I had my plumber separate the main into 3 separate shut offs for each unit. At the shutoff, he installed the submetering device that you plug in and it tracks all water usage downrange.
The billing is nice, provides a copy of the tenant's water bill, trash, and submeter charge on the bill that my property manager provides. One can plug in their own water/sewage rates, and up to 3 other miscellaneous charges. I pay $17.70/month for the 3 metering services, which I pass onto the tenants.
I have no experience with the point of use meters. Their customer service sucks though, with long delays for emails, and they never answer the phone. I hope this helps you or whoever may choose to use their service.