Radley Balko is normally a pretty clear-thinking guy, but his advice to the President-elect is not smart. The President is unto himself, a separate and equal part of the government. The President cannot make demands on either of the other two branches, and they should not be able to make them of his. While fore swearing Executive privilege sounds great, it would be a show--when the stuff hits the fan, protecting the INSTITUTION of the Presidency from the encroachment of the other branches is a duty each President owes to his successors.
Besides, I'd LOVE for anyone in Congress to "open" his or her office up, so that the advice he or she receives from staff is just as open as that they would seek from the President. Are you aware that all those "save your email" requirements levied on the office of the President do not apply to the Congress?