I've experimented a little with this substance recently. About a month ago I took ~1.3 mg. Slight stimulation, enhanced colors, music, etc. Reached a light (++) about two hours in. Started coming down at four hours, slept no problem at six hours. Two days later, I took ~3.0 mg. I don't know how much tolerance I had, but I'd guess very little since an experiment with 4.0 mg weeks later scaled appropriately. My 3.0 mg experience was comparable in intensity to maybe 150 ug LSD or 2 grams of average shrooms. Reached a light (+++) by two hours which plateaued for maybe three hours. Mild confusion and restlessness like LSD, but annoying jaw tension. A cup of strong tea seemed to help. I listened to music in the dark with little visual activity, but occasional oneirogenic visions. The comedown was a two-sided experience. About seven hours after taking the DOC, the psychedelic effects dropped off pretty suddenly, but I continued to experience light visuals for a few more hours. I feel I could have found sleep, but it was morning at this point so I stayed up.
At 4.0 mg (with no tolerance), DOC revealed its potential. I dosed with a couple friends. I was up to a solid (+++) after two hours. There was some real LSD-like confusion going on (e.g. thought loops), and some strong CEVs. At one point, I closed my eyes and watched blood pool up in the crevasses of a non-newtonian fluid (like in those videos where they put it on a speaker). I watched this hellific scene in a very clinical, detached way like I might do LSD. Generally, I was glowing and chipper. I didn't keep track of the timeline too well, but I was fast asleep 11 hours after dosing. I woke up at the 14 hour mark sleepy with a mild afterglow, but completely sober with zero hallucinations.
DOC is pretty similar to LSD, but a little more visual and a little less deep psychologically. Negatives were jaw-tension and diuresis. It lasts about as long as LSD for me, though it comes on slower. The come down is comparable, but the visuals continue mildly for a couple extra hours, and it's easier for me to find sleep whereas LSD won't let me. Claims of 20+ hour durations seem exaggerated to me. Maybe it's just a matter of dose, but altogether, 4.0 mg didn't last any longer than 3.0 mg. There was a lot of pent-up physical energy that craved release. I think DOC would be great for outdoor excursions if one remembered to stay hydrated.