CONF, There is one factor about your view that linked controls are 100% safe that bothers me. How does a commander (for instance) guarantee that the other pilot will allow corrective action to take place? After all there is no priority button on the 734 (for example) control column is there? What happens if "I HAVE CONTROL" or "TAKING OVER" is not complied with? This could be the case of the junior crew member dealing with a commander who is making an error (The "I will not be humiliated by a go-around, I can salvage this" syndrome), or deliberate violation, or is even incapacitated. You must know that these circumstances have led to accidents/incidents in the past. Perhaps some of these incidents may have had positive outcomes if a priority system had been available. Get my drift?