Cold extraction is far more preferable to brewed coffee. The flavors are better and less acrid. A brewery in Indy uses a dry beaning extraction where they just dump freshly ground coffee into a keg of the beer and let that steep for several days. They then meter that beer into the total batch to taste.
By the way, a big dark roasty coffee is not always the best coffee in beer. That same brewery produces an occasional beer that starts out as a Cream Ale and they add a relatively fruity African coffee. That is a truely outstanding beer that is far out of the ordinary. The light bodied cream ale is not overwhelmed by the fruity and lightly roasted coffee flavors. They call it Cream n Coffee.
