A powerful disassociate psychogenic, usually gathered from cough syrup. It is a synthetic opiate replacing heroin and opium in old-time syrups. At a low dosage (30-60mg), it suppresses the cough center of your brain.
At higher dosages (500mg-2000mg, depending on weight), it is a powerful full-blown psychogenic that can cause major OBE, time distortions, hallucinations, and a general disassociation from reality (hence its a disassociate).
People who dont like it usually a) cant handle the intense experience or b) tried drinking cough syrup too much. It can be legally ordered as a pure powder from many net sources, and rather cheaply (cheaper than syrup).
Its usually measured in plateaus, with one being the lowest (500 or so mg) and four being the highest (1.5G ), with each stage getting closer to full-blown hallucinogenic disassociation.
If you havent done at least 500mg (around 1 1/2 of Robo MS), then you really havent tried it.