In reply to BStar:
There are routes which have changed almost beyond recognition since some guidebooks were written. A good example is the Tournette Spur, subject of a recent thread here, which has evidently become a serious undertaking but used to be given PD. The north slope of Mt Blanc de Tacul was safe and very easy indeed when I did it in 1987: a smooth, even snowfield. It is now often heavily crevassed and threatened by seracs. And there are some routes which, inexplicably, were once popular, where you need to be a loose rock (or dust) addict with nerves of steel: an example here would be the traverse of the Gandoliere in the Ecrins, where many have had epics expecting a nice, non-serious warm-up.
So always seek recent, well-informed advice. Hut wardens know the local score better than anyone. Equally, you can sometimes get lucky, and find things much easier than expected. The Brenva Spur changes dramatically from year to year. The approach to the Col de Peuterey can be fraught and highly dangerous. Or it can be a trivial, pleasant romp. I could go on...
Post edited at 10:51