I don't mind lack of routine as much as I mind lack of sleep...
Not much of a routine when its summerholiday... But not getting enough sleep is breaking me up much more. I haven't been able to sleep enough for over a year now, though. I usually fall asleep between 1 and 2 am - as earlier then that I'm usually to anxious to go to sleep and then wake 3 to 5 hours late from a nightmare...
I get the being sick thing too, 2 summers ago I was in bed all summer... That doesn't help things for sure.
So, for me a routine helps but I can do without, not enough sleep is far worse.