Approaching the end of my second season with the stove (2nd season with any outdoor stove actually). Last winter was much more severe with many days failing to reach above zero, and many lows in the -30s and -20s. This year we've had occasional lows into the -20s (twice maybe?) but many mild days, including 50s and 60s this month. These are the things I've learned through two years now of working with the stove.
1. Smaller, dry pieces of wood, loaded to the same volume as large wet pieces of wood, burns much more efficiently. I was stoked (no pun intended) to be able to load it full with big rounds last year and then reload it 24+ hours later. That led to a lot of smoke. I get the same burn times now with splits or smaller rounds that are dry.
2. Keep the ashes low to keep the firebrick exposed. I have the non-shaker version. Last year it seemed the stove lasted longer between loads if I had ash/coal bed piled up almost to the door. This year, I've shoveled out 20 gallons of ash every one or two weeks, to the point that it looks almost like the fire won't relight because there's so few coals in there that I'm throwing logs onto. It burns way better this way. The firebrick help keep it hotter and the fire can relight easier. I make sure to rake it enough so the ashes keep falling into the cleanout chute, which leads to the third thing I've learned...
3. Keep the ash cleanout chute cleared at least every week. This allows the airflow to be much more efficient to get the fire going again, and to burn it hotter once it's going as the air is flying in from two directions with maximum speed. When it's burning efficiently, I see only heat coming out of the stove. When the coal bed is small and the ashes are not in the firebox, I get a blowtorch of flames shooting up from the chute when it's burning with the blower on. I'm assuming it's from small coals falling into the chute that are getting completely burned up to ash. That really helps in the efficiency department.
4. Keep the diff longer instead of shorter. Last year I had it at 7 degrees. This year, 12 degrees (190 set point, fan kicks on at 178). I've thought about trying to lower it further, but it's been working so well this way I don't want to mess with it. Even in the warm 50s and 60s weather we've had this month, I still leave it set there. I thought I'd have to lower it so the fan kicked on at about 183 for the warm weather, but I haven't had to. Probably because:
5. Don't overload it. Load just enough to get to the next fill. I aim for 12 hours. 98% of the time, my aimed-for-12-hours-fills would last about 16 hours or more. Less fresh wood allows it to burn more of the coals completely to ash, which aids in raking the ash into the chute, which aids in keeping the ashes low, which keeps the coal bed low, which keeps the firebrick exposed, which makes my life easier!
Bottom line, I'm really liking this stove. It's heating 5200 square feet between a house and a detached garage, and DHW, and working wonderfully.