Not in my experience i burn some soft woods in the shoulder seasons and yes with them i only have coals in the morning. But once it gets cold i burn ash oak hickory or locust mainly and i can shut the stove back allot harder and still maintain stack temp.I burn higher btu softwoods of course but that doesn't seem to matter much for burntimes since I still got the same 8-10 hours on low as everyone else in the world. What seems to happen when folks burn high btu hardwoods is that the heat output goes up but burntimes stay constant.