Scagnattie, I was more about the devastating effects and potential for abuse, rather than the preference of the two. All dopamine agents make you feel on top of the world, regardless of preference. Especially those potent dopamine agents, they will make you want more after the initial dose, you will chase the high regardless of your previous convictions that you set for yourself. It's the nature of dopamine that makes users crazy about chasing the high. Dopamine itself is a major factor for the state of desire in human brain, as well as judgement and pleasure. That's why it's so easy to have a line of mephedrone or coke and redose excessively to keep the good feeling going. Because after releasing huge amounts of dopamine makes you feel so great, when you hit the baseline, you are bound to feel negative due to dopamine depletion, which takes time to regenerate to normal levels.
What I'm trying to say is that it's much easier to spend multiple nights scoring uppers, trying to keep up the rush, not wanting to come down, with judgement being so fucked that you just don't care about the external world, consequences or responsibility, because all you want is keep the party going. You tend to lose track of time and reality on uppers, it's a very repulsive spiral and it's hard to stop in the middle of the binge and ask yourself what the fuck am i doing? You usually tend to realize the situation 3 days in, after putting your heart/CNS through hell, 200bpm on a meter, massive vasoconstriction, dehydrated, depleted of nutrients, vitamins, looking like hell, regrets that mess with your head, anxiety, depression, completely wasted veins/nose, wishing it never happened.
To me, I'd rather be a heroin addict, scoring the deal, enjoying my day, eating a proper meal and going to sleep with a smile, rather than be in anxiety ridden binge, chasing after the high that is never enough and seeing yourself afterwards looking like a wreck, arms swollen, painful, covered in dried blood from digging with blunt needle full of blood clots, digging for hours in the same position lost in the obsession and desperation to find a vein and administer the dose, missing previous two, wasting shit.
Of course it's a different addiction, cause binging on meph or coke will last few days and then you recover for few days, so it's not a constant, every day urge to score. Neither of them is nice, especially waking up sick, trying to scrap few pounds for heroin, but I can in confidence say that I would chose this over crazed, obsession filled, blind binges on uppers that will FUCK your health.