I haven't tried peyote yet, but I know mescaline through peyote's cousin, peruvian torch.
It was like acid, but calmer and fuzzier. I had to eat a lot of incredibly bitter cactus goo, and I was sort of nauseous throughout the whole experience.
It was really good though, I felt very relaxed and my friend and I spent most of the night sitting on our floor watching the walls move or playing guitar or listening to music.
It's something I want to try again, but right now I'm more interested in experiencing a full blown psilocybin trip. I've tried it twice but both times I just felt a bit buzzed.