It is possible to characterise him as a Pope who has been much misunderstood, but I think it is also important to recognise that he is a Successor of Peter whose stature matches up to that of his immediate successors. But it simply isn't known, perhaps largely to the media coverage that he attracted, though I was not around at the time to know how true that is.
My own thought has been that, at some key points in his pontificate, Pope Paul appears to have acted with a vivid sense of his charism as the Successor of Peter. What I would dearly like to see is some investigation as to whether or not at these moments he acted in response to an immediately given charismatic intervention of the Holy Spirit. Of the nature of things, we might never know; but one can perhaps nevertheless see clearly a faithfulness to his calling as Successor of Peter.
One such moment might be his attribution of the title "Mother of the Church" to the Blessed Virgin Mary during his address at the closure of the second session of the Vatican Council (n.21 - no English translation on the Vatican website), when the Council itself had not seen fit to address her with that title. Hans Urs von Balthasar subsequently identified this as vitally important, and it certainly characterises the sense of Marian/ecclesial existence that is my natural environment post-Vatican II (as opposed to Marian devotion as some kind of "additionality").
Another has to be Humanae Vitae, and Pope Paul himself seems to offer a hint at this in his introductory remarks in the Encyclical:
6. However, the conclusions arrived at by the commission could not be considered by Us as definitive and absolutely certain, dispensing Us from the duty of examining personally this serious question. This was all the more necessary because, within the commission itself, there was not complete agreement concerning the moral norms to be proposed, and especially because certain approaches and criteria for a solution to this question had emerged which were at variance with the moral doctrine on marriage constantly taught by the magisterium of the Church.And the last possibility is the Profession of Faith since known as the Credo of the People of God, delivered as the homily at the Mass to conclude the Year of Faith and delivered just weeks before Humanae Vitae was published. It is one of the most striking examples of "confirming the brethren int he faith" that one can read.
Consequently, now that We have sifted carefully the evidence sent to Us and intently studied the whole matter, as well as prayed constantly to God, We, by virtue of the mandate entrusted to Us by Christ, intend to give Our reply to this series of grave questions.