The longer the rest the better the end result. I stopped using a cooler about a year ago I let it rest on the counter for a few hrs and slowly cool down into the 150's the result is better texture and a moister end product. As it cools the fibers relax and the gelatin lays in between them making it moist. If I need to hold past two hrs at that time I will put in in a low oven to keep it warm or a preheated cooler. Holding in a cooler or a low oven straight from the smoker it will continue to cook and the gelatin will still be runny ending up on the board or all over you hands not locked in the meat leaving you a dryer product. Also with a brisket never slice more than you can eat. slices will dry up because there is more surface area. I cringe everytime I see a brisket post and the whole thing is carved up it always looks dry.
I never met a Cow that I didn't like with a little Salt & Pepper! Certified PORK-A-HOLIC