Product review (5 stars): Couldn't be more satisfied
Purchased this to complement our Rinnai tankless (gas) hot water heater and had it installed on a dedicated pex return line.  Also purchased the remote unit which we use in our bathroom furthest away from the Rinnai, about 40 ft.  Drilled a hole for the control button in the cabinet under the kitchen sink which is about 12 ft. away.  Once you're used to the time it takes to heat the water in the whole recirculating line (at most, 59 seconds) it works great.  If you don't use an "on D'mand" installation, Rinnai will reduce their coverage on their tankless unit from 10 years to only 3 years.