I bought 4 Nobos. They are clean, quiet, fast enough, and best of all have a "lifetime warranty" that I plan to make use of when they die.
https://www.nobo.com.au/en-au
What am I missing? These things just look like fancy resistance heaters, exactly the same efficiency as a $15 space heater (significantly less efficient than a heat pump).
No they are not efficient, but my power is almost free, and renewable. Heat pump hardware is very expensive and not as flexible.