Multifuel.

Coal burns hotter and longer in my experience…I can get the house ridiculously warm with it.

Wood for the aesthetic.

Deepest Darkest West Wales here so both coal and wood are readily and cheaply available…my combined energy bills are half that of what I used to pay in the South East for central heating alone.

what trail_rat said

a good wood firebox is nice and wide, but not that tall; the “long” dimension really needs to be horizontal so you can stuff a nice long dry log in there flat on your aesthetically pleasing, glowing bed of ash

a good coal box is narrow, shallow, and tall, so you can get a girt big tall stack of it going good and hot at the bottom of the stack

most multifuels seem to be a converted wood box and don’t work quite so good with coal unless you stuff them full of firebricks (bodge)