I had a buddy who claimed he never really experienced "heavy" withdrawls when he would run out of pretty much anything from oxy and opana to heroin, he seriously could do that shit for days on end, months on end actually, and then stop, and he wouldn't look the slightest bit sick, I fucking envied this dude so much! I don't understand how that is possible, out of full agonist opiates/opioids I have used opana and H have been the worst, opana being a bit worse than h usually.. it sucked ass for me, just like the majority of people, and I am another person who has a stupid super mega fast metabolism, like I would rail a couple roxy 30s and be sick in 1-2 hours if I didn't redose with oxy or some other opi, it was fucked... and it was the same with pretty much all opioids, a diaudid 8mg done IV would last me all of fucking 30 minutes tops! that would piss me off...but boy did those 30 mins feel amazing... Now subs, those motherfuckers are without a doubt the worst opioid (even just being a partial agonist like they are) I have EVER withdrawn from! seriously, they blow oxy and heroin withdrawls away! way worse than any full agonist I have had WDs from... partly because of their long half life, and how strong of an opioid they actually are, a lot of people don't know that, but they are a VERY strong opioid even though we don't usually feel them as being a strong opioid, they are something like 50x stronger than morphine(I think?), they just don't work the same way, as they are a partial agonist opioid blocker.. That is just my experience with shit I have had WDs from, I have heard methadone is by far the worst opioid there is to withdrawl from, but luckily have only taken them in between doing oxy and H, on the days when that was all I could get, 'dones, and there was no dope/oxy to be found(and round my way, that is VERY rare..).