I think how one deals with a death is often in direct proportion to how much one feels like there is unfinished business/lost chances/regrets, as well as the circumstances of the death (natural, violent, lengthy disease etc).
When hubby's mother was hit by a train (suicide + medication problems), his sister (usually the 'cornerstone' of the siblings) had a lot of...history...w/their mother, and went through all those 'steps', and it lasted for quite a few years. My husband, however, hardly blinked - he'd already said his good-byes on an emotional level years before, if that makes sense.
Myself, I typically skip the first three steps and go right to Depression, if I mourn much at all. Denial, anger and emotional bartering I do with the living, not the dead.