The major strength of the director style of leadership is that it is forceful and decisive. Directors do worry about what others think but instead simply make decisions on their own. The downside to this is that directors do not do a very good job of making their subordinates feel valued. They tend to be very harsh when errors are made and they do not allow their subordinates much of a chance to have a role in the decision-making process. Subordinates tend to feel like they are simply the "hired help" and not important parts of a team.
The developer makes subordinates feel much more a part of a team. Developers allow a great deal of input from subordinates. They share credit when credit is due. They try to cultivate the abilities of their subordinates. All of this can lead to a very good climate in the workplace. But developers can go to far. They can sometimes fail to exert needed control and discipline over their teams. This can make for a lax workplace with no clear sense of direction or urgency.