Spoiler alert! A new study has found that plot spoilers don't ruin stories for readers. Using ironic-twist, mystery, and literary short stories by authors that included John Updike and Agatha Christie, researchers from UCSD's psychology department found that the participants preferred to know the plots for all three types of stories, but especially the ironic-twist and mystery ones. Their conclusion is that plot isn't as important as we may have believed it is. One of the researchers, Nicholas Christenfeld, said, "Plots are just excuses for great writing. What the plot is is (almost) irrelevant. The pleasure is in the writing."
An argument for enjoying the writing vs. the plot points is that once you know what's going to happen you're able to relax and savor the story better than if you're just rushing to get to the end. But I think that's the beauty of reading a book for the second time. You need both experiences to really devour a good story — the first one being emotional and suspenseful, the second being pensive and comfortable. Do you enjoy the plot or the process more when you're reading a book?