...... it does not burn as much fuel in flight and is far easier to maintain
The Casey heater burns no fuel, nor does it use bleed air. It's a very simple idea that uses a muff around the hot end of the engine, and an electric blower.
It can be a bit of a bugger with chafing that
can occur on the discharge air tubes of an Allison 250, but far less weight than a Janitrol and no power loss of a bleed air heater.
No idea if new/spare parts are still available though.