Some folks are very sensitive to smoke flavor and very little might be off putting to them while not nearly enough for others. While you may have not had a fire, was your smoke thin, blue and wispy or thin and white? Thick and white which is not optimal can produce a bitter taste. Look at your wood box for heat discoloration and try to place your wood in a part of the box with less discoloration, a cooler portion of the box. It should smoke slower/less thick. You can also try the foil boat to slow down the production of smoke.