In reply to Kieran68:
+1 for the Constant topos.
Nevertheless from my experience, a "F" grade in Ecrins often has much more and more difficult rock than the snow plods in Valle d'Aosta!
E.g. Pic Coolidge is rated F containing an UIAA III- crux and quite a lot of scrambling and route finding.
Same for Rateau, F/F+ but rock III.