Since this is a highly personal question, we can only brainstorm some possible responses and experiences that students have when they read a graphic novel as opposed to the original text.
Some students feel relieved because graphic novels tend to be much easier to read and much shorter. They are also less complex and focus mostly on the primary storyline without including much in the way of secondary plots or detailed characterization. They tend, in many ways, to be a summary of the original text. Some students appreciate this for the sake of understanding and time.
Some students also appreciate the visual aspects of a graphic novel. The graphic novel of Parable of the Sower is vividly colored, and its pictures illustrate the themes, characters, and events of the novel in creative and interesting ways.
Other students, however, feel cheated by only reading the graphic novel version. They believe that they are missing out on the intensity of the plot, characterization, and language of the original text. They want to know the entire story in the author's full range of words, and they regret losing elements like figurative language and the depth of meaning in the original novel.
Other students, too, dislike graphic novels because they force a visual interpretation upon them instead of allowing them to create their own mental images of the settings, characters, and events. These students enjoy creating a “movie” in their brains as they read and seeing the story through their own eyes. They dislike the graphic novel's insistence on presenting pictures to them.
Finally, still other students enjoy perusing both versions, comparing and contrasting them to see which one best embodies the story for them.