Faulkner may have chosen to end with a more coherent voice, because the last chapter ends in the present.  The previous chapters all lead up to the events of the present, and the eventual collapse of the Compson family.  Even though there are elements from the present in all of the chapters, they focus more on how the past has influenced the present.  Dilsey's chapter shows how all of  the past experiences talked about in Benjy, Quentin, and Jasons' chapters lead up to the end of the Compsons and the end of the Old South.   I am pretty sure that Dilsey's chapter is the climax of the book:

Faulkner's choice with the narrators of the chapters has an enormous impact on how we read the book.  Benjy's chapter is just a giant mush of memories and sensations, which is sort of how we remember the past as children, which is basically what Benjy is.  Then Quentin's chapter starts to clear up some of the things in Benjy's chapter, but it raises new questions about what really happened.  It is very surreal, much like things that we remember just having happened a couple days ago.  This is pulling closer and closer to the present, and the climax.  Then comes Jason's chapter, which is very plainly stated, and in my opinion, sort of boring.  But I think Faulkner intentionally chose to write it this way because it comes even closer to present events.  It is like someone telling a story about something they just did.  And finally Dilsey's chapter, which has really rich imagery and sensory detail, because it is most in the present.  I think Faulkner wanted the reader to feel like they were there with Dilsey at that moment, and his words help the reader to visualize what is happening.

Looking back on the book, I would say my favorite part was the entire experience after finishing it.  I was not really enjoying the book until I could look at it as a whole when I had finished.  When I was done with Dilsey's chapter, I realized what Faulkner was doing with time by having the narrators split up the chapters, and the book started making sense to me.  I didn't understand this until I was done.  Now I would say that this is one of the most interesting books I have ever read because of the way it was written.  I think that Faulkner was really innovative, because he perfectly captured what time is like, and memories.  This ties along with the meaning of the book.  I think Faulkner shows the effect that time has on memories and people.  In a way, he proves that time isn't just a linear thing, but something that can make someone's life completely unimportant in a millisecond.  Faulkner showed this by telling the story of a family and a culture that is falling apart, but he tells the story as a person would have lived it.  His story doesn't just have a start and an end, because everything that happens is connected.  He did prove that time can make a life, or a family, into nothing.

I didn't like Jason's chapter very much for the obvious reason that he is a horrible person, but also because I didn't like his writing style, and I found his discussions of the economy extremely boring.  I thought that this chapter would clear up some of the events of the past chapters, and it did help to find out what Caddy was doing.  But I felt that the rest of the chapter focused more on Jason's complaints about his job and his investments, which were not interesting to read about for me.

Jason's character is selfish, sexist, racist, dishonest, and cruel.  This is all supported at different points in the text, so I will talk about how each one can be proven with the text.  Jason's selfish behavior is shown by the amount of complaining that occurs in his chapter.  He continually talks about his problems, including his job, his investments, his Mother and family, and his town.  He never once considers what it must be like for any of the other characters.  He never thinks about how hard it is for Caddy to not see her child, and how hard it is for Dilsey to keep the family together.  Faulkner also shows how selfish he is by using the repeating phrase "I says" over and over in the book.  The repetition of this enforces his selfishness.  His actions in the book also support this because he steals money from Quentin, among other things.

He has many sexist and racist comments throughout the book.  His opening line of the chapter proves this, but also his treatment of Caddy when he says: "Just like a woman. Six days late.  Yet they try to make men believe that they're capable of conducting a business.  How long would a man that thought the first of the month came on the sixth last in business... Things like that never occur to a woman" (120).  This is just one of the many things he says that show his attitude towards women.  He thinks that business and home shouldn't mix, and that women should remain in the home because they are incapable of doing anything else.  His racism comes with his treatment of the household staff.  He complains several times in the book about feeding the staff, and how they never do enough work.  The language he uses to describe African Americans shows his racism.  He even threatens to hurt Dilsey, who is probably like 85 by the time his chapter comes around.

Jason's cruel behavior was most clear to me at two different points in his chapter: the time Caddy pays him to see her child, and the time he burns two tickets that he isn't going to use rather than giving them to Lester.  On both these occasions, Jason shows absolutely no sympathy for the people around him.  He is entirely absorbed by his own problems.

I am not sure that I completely understood Quentin's section of the story.  It is very hard to follow the plot happening beneath his other thoughts and memories.  But I really like his writing style.  I like the way that he combines the past and the present, because the way he thinks makes sense to me.  Unlike Benjy's chapter, I felt more able to follow the connections between the present and his past memories.
I thought that his obsession with time was the most interesting part of the chapter.  His father says at one point in the chapter that time will make all of his problems go away, and that he will forget what has happened.  I think that partly, he doesn't want this because it makes the experiences less real, but he clearly wants to triumph over time by ending his life.  He has to make sure that time goes on by checking to see that some clocks are exactly on time, but he wants his time to be over.
I also noticed that he seems much more observant about people's characters than the other people in the story.  He is able to sum up his mother's personality in a few words that she spoke at one point about all of the things she has to deal with.  And he perfectly captured Caddy's personality, and her wish to rebel in every way from her family.  He was also able to show personality in the servants of the household.  I think that other narrators from this time period would not have seen their workers as people with personalities, but Quentin clearly understands people more than his other siblings do.
One of the things I can't decide about Quentin's character is if he is a good person or not.  I am not entirely sure what his motives were for protecting Caddy, and he seems overly obsessed about what happened to her.  This could be a sign of how much he cares about her, but it comes off as pretty creepy to me.  But he does seem to care about Benjy, even if it is just for Caddy's sake.