This feels like a good audience for Erowid.
replies(1):
The first plateau (1.5 to 2.5 mg per kg body weight) is described as having euphoria, auditory changes, mild stimulation, and change in perception of gravity.
The second plateau (2.5 to 7.5 mg/kg) causes intense euphoria, vivid imagination, and closed-eye hallucinations.
I like recovered.org's description of fourth plateau dose experiences:
The fourth plateau (at extremely high doses) can cause complete disconnection from reality, a sense of entering “another universe,” and a loss of sensory contact with the environment.
Sounds about right. Definitely kills some brain cells, but a hell of a ride. Would not recommend it if you don't like dissociatives.