Ralph, I think you got a "bum" Akorn.
Mine had a few spots that leaked around the ash pan, and I lifted up the screws and re-tightened, and all is good.
I get 1-4 degree accuracy with 18+ hour cooks (at smoking temperatures) with these settings.
P: 2
I: .0035
D: 6
Fan on above 50%, min at 5%, max at 30%, Startup at 70%
Servo fully open at 100%
Fan/Damper is the Adapt-a-Damper
Of course, these are settings for smoking "200-300". I never saw any real reason to use a Kamado for cooking pizza, or doing any other high heat cooks. Pizzas cook fast enough, so I really never saw any reason to use the HM for it.
I've cooked chickens on my Akorn at 350, and held VERY steady with no more than 2 degrees deviation over a cook. Any temp over that, and I'll just pull out my kettle to do some "grillin'"
Fire is lit with 1 alcohol soaked cotton swab, or sometimes 1/2 of a weber cube.
Once the swab (or cube) goes out, I let the HM take over with the top damper fully open until the temp reaches 140 then choke the top damper down to a sliver past the "holes" (about an 1/8th inch on the straight section just above the holes).