Mescaline vs. Mushrooms/LSD

[Nature Boy]

Although SWIM was planning on trying mescaline (in San Pedro form) a few weeks back, he never got around to it because of his obsession with shrooms and because of late, LSD has become available to him again.

Having done LSD just this past weekend and without wanting to get into the habit of doing it week after week, he is now interested in finally getting around to doing San Pedro. Basically, he wants to know a little bit more about what he should be expecting when he's tripping on this.

How long does the trip usually last and are there after effects that last for hours like LSD or does it wear off quickly like mushrooms after the peak? Is the nausea caused by the San Pedro really all that bad? Is vomiting unavoidable? How does the hallucination compare to that of shrooms and acid? Is it similar or is it completely different? I also hear that bad trips are highly unlikely with mescaline cactus. Is this true?

Any decent replies would be welcome. Thanks.