The visuals are very varied and have been described a lot, but I would like to point out the differences in 'image quality' that I've experienced.
2C's CEV's were like a low-res image full of static, the pictures assembled themselves out of a flurry of dots and faded away into chaos when out of focus.
Tryptamine visuals were surreal, with a larger than life clarity and intensity, with bright, saturated, computer graphic-like colors. They turn the world into fairyland.
LSD visuals were the most photorealistic for me. No distortion, no exaggeration, just cold, solid, immediate reality. Imagining something and seeing it come into existence before my mind's eye, evolving as I shape it, with exquisite intricacy and complexity, letting me sculpt reality in the form of my imagination.