Has anyone had direct experience with changing over to one of theses systems and could they comment on the efficacy.
Re: efficacy/accuracy – all meters used for trade are required to be Pattern Approved (by the National Measurement Institute) and WaterMark certified.
Re: leaks – these can either be ‘deduced’ through data validation (monitoring of usage patterns) or ‘detected’ by the sub-meter (as continuous flow as low as say 3l/hr), with alerts via SMS for example.
Now borders have reopened you will likely see greater availability in NSW of the options currently available in QLD, including solutions specifically designed for sites with ‘pipes buried in the building structure’ (as noted by kaindub).
A reputable supplier should be able to provide referees as well as indicative outcomes for comparable sites.