I found the film version of the Pope Joan story compelling viewing because it conveyed the force and importance of Joan's spiritual calling yet portrayed her as an breathing human being (this may be somewhat ironic since it is possible she is only a legend). Here is a woman who hears God's voice and the voice of carnal longing. She is neither the lowly whore nor the ethereal virgin. Also, it is refreshing to see films where spirituality and belief in God are taken seriously.
I found the performances to be excellent, especially those of Liv Ullman and Trevor Howard. Ullman is very good at portraying the vertical pull of spirituality and the wrenching ambiguity of living in the material world. Trevor Howard's performance was utterly convincing. Also, Susan Winter had a quiet presence about her in her brief performance as the young Joan, which impressed me. What a tenuous thing to be a young girl in the Medieval age - what a microcosm she is of all human existence.
This film has its flaws, most notably the disjointed editing and jarred pacing. I do not quibble, however, with the less than ideal sound quality of the dialog or the occasional white lines which momentarily appear on the screen now and again because when I watch a film, I accept the film on its own terms; I do not wish it was something it isn't - a film made on a modest budget in 1972 should not be expected to look and sound like a mega-budget blockbuster filmed in 2006. On the whole, this movie is a success.
Cautionary note: not a movie for kids.