I don't find it to be more sinister as much as I find it to be more variable (can be sinister, can be bright). Generally with a normal shroom dose, my experience is a good one with little variation from the mean. I've never had a bad experience on shrooms. With 4-ACO-DMT I have had one REEEEALLY bad experience (though introspective) on 30 mg and one truly amazing and bright experience on an insane 100mg dose (that was a ballsy move).

I typically played it safe around the 20mg level and it was either a meh or a really good experience. The bad time I had was because I was inexperienced with the substance and became annoyed when it wasn't what I initially expected (more of a shroom type of experience) so I tried to direct the experience, which is a big no no. When I had the amazing experience, I prepped myself by watching stand-up comedy during the come-up and I had a bottle of wine just in case I experienced any anxiety (worked on a previous bad experience, so I always keep alcohol or benzos handy for tripping). That time, I force myself to sit and roll with whatever came.

I suspect the variability has to do with the fact that 4-ACO-DMT is an active compound on it's own AND it is likely metabolized into psilocin, which is another active compound. Thus, the levels of two active compounds are going to vary by experience and also during each experience.

I have both insufflated and taken it orally. When I insufflated, I found the experience to be lacking. When taken orally, I had a much greater effect. This is likely due to bypassing first-pass metabolism which would be likely to reduce the c-max of the pcilosin.