I had a friend who liked Ketamine, and went into the K-hole. It always sounded too intense for me. I tried small doses of it and I never really liked it, but hearing him describe the feeling of coming out of one was fascinating. It was like a brain reboot; layers of subconscious and conscious brain functions like pattern recognition would return sequentially. He said it was an incredible experience, and gave him unique insight into his own brain. When I was doing hallucinogens, I don't think I ever tried N,N-Dimethyltryptamine, but I do remember 5-Meo-DMT, which if I recall had a particularly heavy body load. It had some closed eye visuals, but most of the trip was very internal and psychological; out of all the drugs I sampled, it wasn't my favorite. I think I liked 2C-E the best, experiencing synesthesia was just so much fun and it gave a lot of that. Just to add, anyone considering doing drugs should approach these carefully and with research. When consumed responsibly, I think they have a fairly low addictive potential and can be reasonably safe, but like any drug, they have side effects.