I'm really only talking about the level of climbing and what he did in Val Thorens may simply be better than he could've done at the Vuelta cause an 80 minute climbs suits him that much more than all the 20 minute ascents of La Vuelta. I definitely think it was a stronger performance than any Giro mountain stage he did this year.
I agree that a climb like Val Thorens perfectly suits Nibali, but I think that was still a level below what he showed in the Giro, especially on Mortirolo. On VT the yellow jersey had pretty much been decided the previous day, and as we saw, the favourites didn't really go all out, at least not from any distance out. Nibali performed really well in the Giro imo.