Yup, I'm super sensitive to serotonergic drugs. Like 1g of shrooms will have me melting into my environment, and getting stuck in thought loops while everything around me melts and shatters apart.
For me, one tab of acid was perfect for the first time. It was still a decently strong trip for me. Couldn't be in public, but alone in private I was totally great. Things were shifting and changing color, and my thoughts were distorted but CLEAR, like I truly understood what was happening around me. I knew the mechanisms of every object around me. Society, air, the earth, clouds, houses. It all made sense, and so much (the public parts) were so ridiculous to me that I was cracking up, so I had to leave. I wasn't freaking out though, except paying at starbucks, but that's it. It's the only psychedelic I enjoy. I don't even like MDMA type drugs because the feelings are too overwhelming if I take too much, and they make me depressed while on them. Same with shrooms. If you aren't prone to depression/anxiety though I think many would say a low dose of shrooms.