I use K in my big stick burner. I use it because it keeps the temps more even than a strictly wood fire. Evey time I added a log the temp would spike until it went to coals, when I was on wood only.
I now use the K to keep the heat even and add wood on the side to smolder to get my smoke, trying NOT to let the wood actually burn but smolder next to the K. I get around 10-12 hours of heat out of a 15lb bag. I only use around 3 8''in diameter Pecan logs to get the smoke.
Since I added the stoker the times are going up and the temps are always right on.
Colt