I guess the "it depends" is the best guide. (Not RMI trip)I bagged myself on Ingraham Flats one year because I just didn't feel well. I had the comfort of being able to walk around, take a nap, pee, poo etc...my friend on the other hand got bagged on disappointment cleaver. I felt sorry for him. He was in the direct sun the entire day, and when our party collected him on the way down, he was wasted and fried from the intense rays of the sun. I guess the moral of the story is, if can sense that it isn't your day, bag yourself in convenient spots and let the others try for the summit.
The great part of the story was that because I didn't exert myself that morning & had the some sense of "team", I was able to stay with my other friend who got altitude sickness - until he was able to recover suffienctly to get down. The others in the group - the bastards - left him at Muir and proceeded to paradise without caring for him. They were just too tired to think straight and just was too anxious to get off the mt.