I kind of hate the kill ring, because I don't know how to suppress putting things into it. I would really like to be able to delete swatches of stuff I don't care about in such a manner that they aren't pushed onto a "paste" stack on top of other things I do care about.
I've also never really understood the benefit of not having "redo". What am I gaining in exchange for the annoyance of having to hit an arrow key before being allowed to "undo the undos" and duplicating a big chunk of my undo history?