I dunno about datura..never tried it..
The puking isnt bad..in fact I have yet to puke with vilca when I take it with ayahuasca..nauseated yes..but only for a quick 2 or 3 minutes..vilca is not really for the faint of heart..it can be like hell, but after that phase it can be like heaven.
It does make you sick for the first few minutes though..last night I took a real large dose of vilca without the brew all at once and ended up purging hard while deep into it..but it felt really nice after, very healing..I even redosed without any problems..
Long live the unwoke.