Get Real: If you are an American I am sure you have heard the adage that
"the only stupid question is the one not asked" about a million times, yes?
OP: Yes, like any long term user I have overdosed and since I am posting this, of course I have been revived. Alot of opiate-naieve or inexperienced users believe that any opiate/opioid overdose would be a painfree experience, like a great big "nod," etc.
Far from the truth. If you do not go under right away you will be so naseous that a raucous night at the bar will seem like tea with mum. Vomiting for 3 days is about the norm from subjective experience and informal polls. It is just as with any poisoning, if you manage to survive it your body will naturally purge it and it is not fun at all.
Hard to say what someone who goes under right away feels, since I can only remember from the injection of Antagonist. Since I was (and am) a long term addict (24 years of opiate/opioid addiction) it was hell, as an understatement. Have you even been in Acute Physical Withdrawal? Imagine the peak of the Withdrawal hitting you in one fall swoop. There is a very good reason why Rapid Detox Practicioners administer general anesthesia to subjects. Basically, you are in a gurney most likely and suddenly seize up and wake all in the same instant, foaming at mouth usually.
Most addicts swear they would have rather died than have experienced a full Antagonist while addicted but I seriously doubt many REALLY wish to have died. At the time though, I have absolutely no doubt that they FELT that way.
Either way, it is far better to edcuate one's self and engage in safe and educated usage.