My Rheem hybrid 65G has been running about two weeks now. So far, outstanding results. We use hot water for two people and have been averaging 1.7 kWh Rheem consumption per day.
I came across the same befuddling advice from Rheem to set the heat pump to 'energy saver' rather than heat pump and decided to ignore it because my 65Gallon tank has a lot of hot water reserve for our use and I'm guessing that the internal programming will not default to heating element usage. The test will happen in the winter with lower ambient. For now it works spectacularly and is averaging a COP of ~ 6 (six !)
Our Rheem is in the garage which has the wonderful side-effect of cooling down the space for free. Funny house, that the most pleasant room in the summer is the garage
I'l have to connect an air supply duct from the outside by the time winter comes along to keep my COP up to desired levels (> 3.0)