I did a test burn last night, set her up with about 12 lbs of charcoal in the basket and 3/4 of a chimney to get her going. Started at 9:30 and by about 10:30 -11 she was down to about 270. I closed the intake a bit more and she dropped to about 250 at the center of the grate and 225 at the edges. I had a few more beers and watched her till about midnight and called it a night at midnight with her holding steady at 256.
Just got up and checked her and she is at 262. I closed the inlet a very little more too see how responsive she is to small changes and she dropped to 249 in about 30 minuted and she is hold there at 249.