In reply to augustus trout: The Auguille de Sialouze is really excellent granite and is bolted but you should take a small rack aswell. The easiest route is Super Pilou which is probably VS/HVS, then Ventre a Terre which is HVS/E1. These are quite big routes of 400m length at between 3100m and 3500m. Then there is stuff on the North Faces above the Glacier noir and some well bolted easier routes on Pointe Louise, Cineastes etc above glacier Blanc. Can definately recommed Soleil Trompeur on the Petit Sagnette, 500m f5+, well bolted, at about 2800m altitude.
I wouldn't discount the stuff in the valley it isnt all just slabs.
If you have a car then head to the Cerces which are 50minutes drive from Ailefroide, limestone, well bolted, between 2300m and 3000m.
All of the above are on good quality rock, as are most modern Ecrins routes,the rock is no worse than other alpine areas unless you search out the loose traditional honeypot routes!
Email if you need more info as I go there regularly as I have an apartment in the village.