It sucks because there's ultimately far more efficient ways to heat a home and the only reason they're not implemented is to try to force greater consumption.
Only one firm in the area could even quote me on one, tried to talk me out of it at every step, and gave me a quote that reinforced their sales pitch. It was literally never going to payback over a combi, which dozens of companies would be happy to install and service.
So, a fresh combi boiler sits on my wall (which is a good improvement over the old), but it also means that I don’t entertain the question again for another 15 years.
I was among the top 0.1% aware, educated, and motivated potential customers of a heat pump and it couldn’t happen.
Anything-to-air wasn’t going to work visually or for occupant comfort. I don’t want refrigeration linesets strung all over the outside, warts on a wall in each room, and after all that having less comfortable heat than hydronic. (On the plus side, it would give AC “for free” [in capital costs].)
Ground source (to water) was my first preference. I’m on a pretty small city lot and the well cost meant for an even longer payback period than an air-to-water heat pump.
Use an electric blanket, and wear an extra layer. This will use far less energy, than trying to warm up all of the air inside the home.