Cooked 3 large butts in the XL:
Didn't do turbo because I had the time and prefer the lo-n-slow bark. Started with lump carefully arranged about half way up the fire ring. Dome temp 250 and 21 hours later, undisturbed lump bed looks like this:
slightly lower after I stirred thoroughly to drop the ash and compact the lump:
all scooped out, could have gone another 21 hours?