I have recently been gifted with some old fujichrome and exposed it just to see what would happen. It was some 220 RDP and 8x10 Velvia, the Velvia expired in 1993 and the RDP in 1995. Both had been stored at room temperature for the last 10 years, so I wasn't hopeful about the results.

After processing, I was quite surprised. Both the films look very good, with no density loss or colour shifts. There does appear to be an increase in grain, but its still pretty controlled, considering the storage conditions.

I exposed the RDP next to some fresh Provia 400, and the results look identical in terms of colour when I put them on the lightable.