i did mine overnight..
i used charcoal briquettes to get the smoker up to temp.. than i added lump coal to keep the heat consistent,,, and used a variety of chips,logs,chunks for the smoke,, (pecan,apple,hickory,oak)
i started at 9pm... after 6hrs of smoke i wrapped it in foil and continued to cook for another 6hrs... after that i placed it in a cooler (still wrapped) and placed bath towels over it for another 6hrs... the brisket was still hot after all that.. 18hrs... and yes i was a zombie but it was worth it
my next brisket will be done the same way.. during the rest period i was able to smoke 3 spare ribs and they were done at the time i pulled out th brisket.. ,,,
i saved the brisket juice and added it to bbq sauce ,, something that i saw on foodnetwork at some bbq joint in texas... everything turned out great including the sauce...