I don't know of, first had or by proxy, another drug as gentle and wonderful as mdma.
It is my drug of choice, maybe once or twice a year because I feel it is unique in the ones I've tried. The risks are worth the reward.
Many substituted phenethylamines are psychoactive drugs, which belong to a variety of different drug classes, including central nervous system stimulants (e.g., amphetamine), hallucinogens (e.g., 2,5-dimethoxy-4-methylamphetamine), entactogens (e.g., 3,4-methylenedioxyamphetamine), appetite suppressants (e.g. phentermine), nasal decongestants and bronchodilators (e.g., pseudoephedrine), antidepressants (e.g. bupropion), antiparkinson agents (e.g., selegiline), and vasopressors (e.g., ephedrine), among others. Many of these psychoactive compounds exert their pharmacological effects primarily by modulating monoamine neurotransmitter systems; however, there is no mechanism of action or biological target that is common to all members of this subclass.
There is a bit of overlap on feelings but Molly isn't like straight amphetamines and opiates don't feel the same at all. If I had to try to correlate the feeling of these substances to sober feelings here is what I would say. Amphetamines are like the anticipation/anxiety of a big event or meeting a new love. MDMA is like being in love, but with everything and everyone. Opiates are like a really long, whole body, orgasm. Just pure euphoria.
Have you done MDMA AND heroin/Meth? More important meth. Because these drugs have a huge overlap when you examine the physiological effects. Pleasure, love and bliss are generated by the same chemical.