I used Default configurations and have tried a few games (system specs 1gb ram, 2ghz processor, Geforce 4), most work well some don't:
Mario Tennis: Still pretty bad effects have been v poorly emulated and some graphics show up as black objects.
Paper Mario: Graphics are fine but the sound crackles a bit.
Beetle Adventure Racing: Some graphical errors (e.g. black objects).
Otherwise, so far, so good, definitely a significant improvement over 1.5
However, I don't think that Project 64 will become the N64's ZSNES till at least version 1.8.