In reply to shantaram:
It is a potentially attractive idea. It requires:
- stable weather
- being fast, 10h for up-and-down is a good time!
Disadvantages:
- you may be held up by slow parties in the upper, more difficult part (i.e. the fixed ropes where passing is difficult)
- you may be bothered by lots of people coming down in the upper part
After all, even though the rush in the morning is somewhat unpleasant, I think it still pays off to start just after the guides and make progress quickly. I did not find the routefinding too much of a problem in the dark. An inspection the previous day up to 3800m (unroped, takes about 1-1.5h going up) helped much, also to calm the anxietey. And, by roughly following the queue in a pre-dawn start, it will anyway be hard to get lost.