Lou, I don't know anyone else who burns coal for heat.
how old is your unit and is the maintenance similar to wood?
do you wear a train hat while shoveling coal?....

likely you have an autofeeder of some sort
No autofeeder unfortunately. This is a Hitzer fireplace insert with a double jacket and blowers. I've had this for about 15 years. It has made a considerable difference in my oil consumption, most years a 300 gallon decrease in oil for the winter.
The maintenance is less then a wood insert or pellet burner. Most days I get by just shaking the ash grates down once a day and it has a hopper to dump the coal in. I get mine in bags (nut coal) 40 or 50 pound bags. I kept the pallets of coal down in back of my little shop and would use the pallet forks and bring up a pallet and set by the house or put 15-20 bags in the bucket and bring up to the house. I dump the bags into 5 gallon buckets to bring it into the house and feed the stove. When your burning stones it doesn't have to stay dry, usually when it's bagged it is actually wet for dust control.
No need to clean the chimney every year, I do it every 5-6 years. Most of the fly ash drops down into the fire box during the summer.
I almost went with a coal boiler 30 years ago in this house but ended up with an oil boiler.
I even considered wood as I have lots of available "free" wood but growing up and cutting and splitting wood for two houses that had wood fires central furnaces, that 10-15 cords a year was a royal pain.
So no autofeeder and no train engineer hat, sorry.
This is my last year burning coal, this summer the coal insert is coming out and a gas one is going in. Artificial knees don't care for kneeling to shake ashes down and if something else happens to me my wife isn't comfortable or really capable of tending the coal fire. That was one reason it was out for the last couple of weeks, surgery and a 15 pound lifting limit would have stopped 40 pound bags and buckets.
Sorry for the long response, but over all I've been well pleased with burning coal, nice heat, a bit more difficult to regulate on warm days. Once I started it this past fall, it never went out till I went in the hospital so it was a one match winter till todays second match.