I know amphetamines and opiates are amazing but what about opiates and benzos? Will the benzo ruin the effects of the speed? BTW the amount of benzos were talking about is 1.5mg kpin 4 hours ago and 2mg xanax 2 hours ago.
I found when going on a amphetamine binge a downer can help it be less jittery, for me once I've been going for a long time I get huge jitters and a downer or alchol removes it. So it's not a bad idea, try it it might make your experiance better if you get a bit jittery after a long time speeding.
What I would do is take half of your normal dose of the benzo at the beginning when taking the speed, and then save the normal benzo dose + the other half that you saved from earlier together for the comedown.
I would save the amps for another day since you already took a decent dose of benzos.
^ Most people wouldn't be nodding off in the corner from that combo, unless they either have a very low benzo tolerance, or took a large dose of benzos. The reason why I wouldn't take a benzo with MDMA is because it would diminish the psychoactive effects of the MDMA a bit. Benzos restrict my emotions, so it would be counter-productive for me to combine them with MDMA.