I just completed my 1st cook and an over night cook on my new 22"
1st, I used original Kingsford to remove as many variations as possible for the 1st run. I used 2 15 pound bags total, the 1st bag filled the charcoal ring. Using the 2nd, I filled a chimney about 1/2 way for the initial light unsing the MM. In hindsight, this may have been a tad too much in the chimney, but it did provide even, full coverage for the ring and the temp came up quick and held steady. I then added 6 chuncks of wood. I added the remainder of the second 15lb bag (roughly 10 pounds) the next morining at the 12 hour point (9:30 am) to get to cook to the evening.
I started with a full water pan at about 9:30pm. I checked it at 11:00 and again at 4:00am. This was overkill, since at 4:00 the pan had PLENTY of water and only took roughly a gallon of water to top it off. The pan would easily make it from 11:00 to 8:00am with no attention.
My cooker sealed up pretty well out of the box with minimal tweaking on the door. On initial light-off and assembly, I held an average of 225 at the lower grate and roughtly 235 at the upper easily with all lower vents fully shut. I bumped the bottom vents to 1/8-1/4 open the next morining at roughtly the 12 hour point to maintain the temps.
Overall, the temps held rock-soild and required no babysitting. I was a little surprised at how much charcoal I went thru, but considering the sheer size of the cooker, using a full water pan and this was a 20 hour cook, it is not bad at all in the grand scheme. I was also VERY pleased with how long the water pan ran without filling. This thing is an over-night cooking machine!
Good luck!
Allen