Everyone always has a choice, but the choice is decided for or against by outer factors.
Simply answered, cause the para-halogenation it is subjectively from my experience a way rushier and actually stimulating substance than 4-MMC. I "only" done 3-CMC and 4-MMC (3-CMC in total in the kilograms range, and 4-MMC not as much but to a way lower tolerance each redose overdoses, not to say to follow this, but learn from my mistakes and prevent them)
Well the stigma around para-halogenated methcathinones is extremely huge and wrong misconception, everything is, some less and some more, but it is calculable. To my knowing, there is not a single research paper that would state that para-halogenation in methcathinones increased the neurotoxicity as to the MMC's, both being way less destructive than compared to desoxyephedrine[methylamphetamine] or MDMA.
The research papers that state severe neurotoxical damage from these compounds made the experiements with such dosages of 4-CMC that would be in the lethal zone anyways, and of course then the neurotoixicity will be severe.
Longer period time of binging ANY drug will result in severe neurotoxical, cystoxical, and in general damage done to the human body and brain. Everyone's neurochemistry and biology and other factors differ from each other, meaning the results will be also highly different from patient to patient
Most of the times, talking about Eastern European areas, the main view on these substances are not even close to legality, as it's being sold on the streets mainly due to a huge demand and crisis, under various names. The percentage of people who purchase 3-CMC for the law status it falls into are very shallow.
Everyone should decide what their personal preference is based on their experiences, some people will prefer MMC's and some the CMC's or EMC's or MEC's, it's impossible to say what is better of, only not if you talk about your own personal preference.