I cook or brown my ground beef in a skillet using a potato masher pressing, twisting, and seperating the meat. I feel it cooks faster than just flipping it around with a fork, spoon, spatula, etc... I think it gives me a better sense to as to if it is cooked all the way through. I also think it makes the meat more crumble like as opposed to clumps. I prefer my spaghetti sauce, shepherds pie, or taco filling not to have lumps of meat.
Just a thought to the cooking process of ground meat.