Except that I don't regard Sunday above any other day. This is not a question of investing Sunday with some legalistic significance that is analogous to the Sabbath of the OT. Ours is called the New Covenant for a reason, but even under the Old Covenant Jesus made it clear that the Sabbath was made for man, not man for the Sabbath.
The point about Sunday worship is that it represents one of many evidences of the passing away of the old order. As someone once remarked, Jesus was physically dead during the Sabbath, which was therefore buried with Him in the grave. Only cultists deny that Jesus' resurrection took place on a Sunday - His day; the day belonging to Him.