I can't remember the useless babbling at the end, but the spider walk scene did make the movie better. For one thing, it looked cool as the blood dripped out of her mouth with that creepy moaning, and two, it made more sense as to why Regan was strapped to her bed.

Did I ever say the scene its self wasn't good? No. It doesn't work in the context of the whole movie. They didn't need it to explain why Regan was strapped to her bed.

Not only did they not need that scene to do so but I don't think there is any need to explain it. Maybe it's just me but I think it's pretty obvious why.

Upon reflection, Sam, I think that I agree with you, and it's that reason why I think people who haven't read the book, really should.

If you read the book and see the movie (not necessarily in that order, actually), then you will have captured The Exorcist, and hopefully have enjoyed the ride.