I have only fired oil on the Svrr 19 and wood on the no 3 Heisler. The oil is a mental job following the engineer and working the oil valve, the draft, the atomizer and the blower when need. The wood burner takes a lot of physical work. We burn 4 ft long wood the size of fence posts or bigger and use short pieces to fill the hole in the wood under the door. You need to keep a solid bed of wood to prevent holes in the fire and you need to only open the door long enough to throw the wood in. The amount of wood used depends on how good the fireman is and if the wood is wet or not. You throw in 3 or 4 sticks, wait a few minutes and throw in some more
Lots of skill and hard work.