Yes. You actually trip on these. In fact, I found them to be significantly more intense then shrooms, though not for the better.

As to dosage: 15-30 grams depending on weight. 15 if you're skinny, 30 if you're fat.

Most of the visuals I saw were in my head. Alot of the trippiness was "Oh fuck I'm dead."

And caps vary greatly in size and weight.