Foil. More consistent. I've used butcher paper once and wasn't a fan... though it was the white stuff, so maybe not the right paper.
Foil holds heat and moisture better, thus the need for the last hour to "crisp".
When doing brisket, I sometimes use a foil pan with a beef marinade/beer mixture to braise it. Best brisket I ever did was without any wrap... just a spritz of apple juice/water every few hours.