You should only tenderize tougher cuts of beef. A steak cut should be well marbled and shouldn't be tenderized too much. Steaks benefit from having the juices seared in.
You wanna pound the crap out of the lower half cuts. Except brisket, it benefits more from low temp roasting or broiling.
But if you are going to tenderize the meat, do it right before cooking. Mostly for sanitation reasons.
