The crux in conditions we had was the big ice field above the horizontal snow ridge. It was hard ice and very intimidating although angle no more than 55 degrees. We were all the more intimidated as there had been a big avalanche kill 2 climbers on one of the other routes on the face day before, then another climber injured by stonefall on our route. See my trip report: Mont Blanc Brenva face 1984.
I'm really stoked on this one, my partner and I completed this by ourselves after a guided party we were leapfrogging bailed. We even bootied one of thier screws! This one really opened my eyes and boosted my confidence.