Well, Whistle Stop, the subject matter is quite different. I think the comparison is made on the quality of the prose style. Personally, I love Faulkner, and I think Kesey is the only one to come close to him.
            Sadly, Kesey's later stuff didn't live up to the level of Notion and Coo Coo's Nest. I'm not sure why, but my theory is that once a writer thinks he/she has discovered the "answer," there's not point in seeking it any longer.