DOC is odd in its dose-reponse curve. That curve varies for me with seemingly no consistency at all. For example, this past Saturday morning I took 1.2mg and had an incredibly visual experience, consisting of long, detailed, fractallized tracers and a visual soup effect, as well as incredible color saturation, but with relatively little mental effects. The highest I've taken it was 5mg, but that trip didn't approach the intensity of my 3.5mg trip which was my best one of all, loaded with ego-dissolving mental effects. The one thing DOC always seems to give me is a powerful visual experience. I've only had a few trips on anything that were more visual than my average DOC experience, and those were my two significant 2C-E trips, which were about equal but different, and n,n-DMT. When I take it sparingly, with long breaks in between, it feels extremely emotionally and spiritually healing, and produces a state of complete contentment with living in the now for the next 36 or so hours. It motivates me to be a better person, more honest with myself, and more motivated. It brings about a massive joy that rivals MDMA except which is much less forced and much more real. I sometimes get unpleasant amphetamine side effects, and sometimes I get none of those. It seems rather random. DOC also shifts my mind into a very piercing analytical state, where I just want to talk and talk and talk and analyze everything I see. It makes it seem as if everything I do, whether it's important or as useless as watching crap TV, is very useful to my understanding of the world we live in. This state usually emerges after the peak ends. During the peak I'm generally rather overwhelmed and it's sometimes difficult to communicate.
Overall, it's still one of my absolute favorites. I also find that taking it the morning after an LSD trip produces a more profound state. I think sometime soon I'm going to try mixing it with something else after the peak ends. Maybe smoke some DMT on it. I also have a feeling that 2C-B would mix very well.
Another thing I've noticed is that the amphetamine body issues do not seem to significantly increase with a higher dosage, at least up to the level I've taken it to (5mg). I get the same issues from 1mg as I do from 5, if I get them at all.