This topic has been discussed in great depth elsewhere (eg.
here or
here).
However just for a quick summary there are a couple of things to clear up. Sometimes people describe a pill as "smacky"... in my opinion, I would think it's fair to say that only someone who's never tried smack (heroin) would describe any pill thus.
Most often, people use the term "smacky" to describe the effects of a pill that in total, doesn't charge them up, or make them want to dance all night. This is common in Australia, as many people are used to speedy pills which make them run around like mad chooks rather than a clean belt of MDMA to put them on their arse in an ecstatic state. You could be right, I know a few people who when they actually get a good pill with a medium dose of MDMA, as soon as they feel the peak building up and they notice that they feel like just sitting down, they're seeking speed or speedy pills to stop them being 'smacked out' by the good pill because it's not what they're used to.
However, on the other hand when someone gets a pill with MDEA, the classic side-effects such as shortness of breath, dizzyness, stoned feeling, weak legs etc., can make them feel uncomfortable if they don't know what's going on. That kind of stoned drop with little or no loved up feelings can leave them wondering exactly what hit em.
These are two situations when people might think that an MDxx pill isn't doing the right job for them.
But just some of the time, the people you notice taking speedy pills (and maybe even describing them as smacky) might not give half a shit what's in them, as long as they get "fucked up" ... they'll be the same ones to drink themselves wretched then have speed and pills and whatever they can buy on the nite so that they can leave reality for as long as possible.
Not everyone cares how a pill 'tests' or if it's MDblah, or knows what serotonin is. Take pill descriptions with a grain of salt, see for yourself, test for yourself - then you won't have to rely on someone elses descriptions or subjective use of the (hopefully diminishing in popularity) term "smacky".
BigTrancer