They work at a constant speed to do the task. Unlike a human, they will not slow down or get bored or start making mistakes that they were not doing earlier. So once they are programmed correctly to do a task, they will do it diligently.
They are versatile because they can be used for all sorts of tasks. They can also do many of the same tasks in different ways. They are diligent because they will do a task thoroughly until it is finished.