thoughts on Camco 11673 Hot Water Hybrid Heat Kit ?

I installed one on my water heater about 6 years ago. The one item I like about it is the low wattage it uses when on 30 amp power. It only use 600 watts instead of the 1300 that a full size electric heater uses.
If you put one on a Suburban water heater. It will require a small anode rod be installed every year. I get replacement parts off Amazon.
Some state that installing this item will void the warranty. Mine was way out of warranty when installed.