Opiates all the way, unless your someone how its obvious your fucked up no matter what your on. Its easy to notice drunk people or ppl on stims, but opiates your just going to seem like your in a really good talkative mood, unless your on a high dose and nodding right out and such. I'd feel completly comfortable walking into a room full of cops to talk to them on opiates and have no fear of any of them noticing im on something, unless like I said, your nodding out and stuff.