This is my view: I consider the leading and following to be the core functions in our dance. The leader and the follower are equally important at all levels and more similar in effort when both partners have developed their adaptation skills and later on the intuitive dance. However at the beginning the leaders workload is larger.
I agree with the writers about the step learning. I also think that both groups learn their own steps with equal easiness. Some individuals learn more easily then others but within the groups of leaders and followers it may be about the same.
Another area to learn is how to produce the lead/leading signals and follow/receive the signals. Think about a basic ocho as an example. Both groups need to learn the signals for different parts of it and during the hours on the pista leaders and followers do develop all the variations needed for different partners.
And here is the end of the list for follower responsibilities as i see it. On other hand the follower has the advantage to reach the level of true enjoyment or intuitive dancing much earlier than a leader. (a leader can experience the followers special level of relaxation and dream about joining her there some day. . . )
The list of the leader responsibilities is longer. At a later development level the conscious mental efforts and physical demands become similar for the persons forming the couple. During the journey from start to that level the leader is responsible and expected to cover for the shortcomings by learning more than a follower.
To begin with I need to know the follower steps - if not, how could I create the signals for an appropriate lead. It doubles my step learning efforts and even today it is mentally exhausting to remember her/my steps simultaneously when I am learning a new sequence.
Then we have the navigation which is much more than walking forward to an empty space on the pista. It is a complicated skill and last mastered. But when mastered the couple can intuitively adapt their steps to the space available while smoothly advancing on the dance line together with others. We can also, as couples, react to the music with different steps but simultaneously with others so the fully developed pista is pulsating to music. You can see this happen on some videos from Buenos Aires milongas.
The most demanding of the extras is the responsibility for content. The steps must be interesting enough and the connection to music needs to be satisfying. Different followers want different content. The leader must know what to suggest.
In the table below the rows present the areas of responsibilities for both groups.
The columns show how much mental/conscious effort is needed for dancing. It stretches from totally conscious steps --> totally intuitive dancing. A variation of the Four stages of competence process!
For me the different stages/periods are these: During the Lead/Follow period the dancing is mostly a conscious process, demanding all my mental capacity. When partnering we both know the steps by heart and can easily adapt to each others; at the best moments intuitively. To reach to the absolute dance the couples on pista must have the skill to intuitively adapt to the other couples as well as to each others within the couple.
Finally and once more - I consider the leading and following to be the core functions in our dance. They are equally important at all levels and more similar in effort when both partners have developed their skills and later on the intuitive dance.