I’ve found GoldenEye to be running around 25-50% under what it should be, depending on how many polys are on screen.
Smash Bros was a bit slow in a 1 on 1 with Mario and Link, but against 3 Yoshis it was really, really slow.
Mario Kart 64 is the best so far.
As others have said, StarFox on the SNES is running like a dream.