With a weather window of only one day and a strong climbing partner we opted to do this classic route in one day from the Montenvers train. It did not help the pressure that a storm was supposed to move in by the evening. Fast hiking brought us to the base in about two and a half hours and in another four hours of fun but very quick simul-climbing we were standing at the base of the summit obelisk. We had been watching the weather all day and as predicted the clouds moved in starting around noon. Now, at 3pm, the weather was getting really worrysome so we left aside the aid climbing (or lasso alternative) and immediately turned around. By the time we were back at our packs at the bottom of the face the clouds opened up and it starting raining for more or less all the descent to Chamonix. Great trip. It is very rewarding when every minute of the day has been used to full extend.