I like how oxycodone can be taken orally, and it's not really wasting it because of the high bioavailability. I've never once sniffed it, this makes it less prone to abuse. When it hits the reward system faster then I believe that makes it more susceptible to addiction. I've never taken heroin orally like I do with oxy, because I feel it would be a waste due to loss of potency.
I don't like how I could never be sure of the purity of heroin - anything could be in it, it could have been transported up someone's butt, etc. whereas my oxycodone comes from a pharmaceutical quality lab. Since I was sniffing raw powder, that made it more prone to abuse. And "heroin" is a term that usually describes a concoction of chemicals that is purchased off the street, with an unknown concentration of diamorphine in it. I generally don't vibe with this, but I've done enough of the stuff to know when I come across some good china white... or do I? How could I ever be certain where it comes from and what exactly is it's composition. This is my problem with it so it's generally a rare treat.
The experiences themselves are similar, but I find that heroin is a little more euphoric and longer lasting. Oxycodone leaves me energized, focussed, creative, motivated, and generally feeling wonderful and productive for the duration of 3 hours or so. I love it... it's my favourite drug, and it works reasonably well for my chronic pain. Regardless of my chronic pain, oxycodone consistently provides me with what I see as the perfect 'high.' I mean, it's very subtle and I would get more fucked up from a joint. But once I came to appreciate the subtlety of the opioid high, I became a connoisseur of it. Heroin is kind of hit or miss, it can be wonderful but it's hard to get the dose right, and get stuff that is actually good quality. I wish there was pharmaceutical diamorphine available, would be really interesting to try. For me it's just way too difficult to get the dose in the medicinal range.
This is just my own personal experience. Everyone's will be different. It depends on what reason you're using, your doses, ROA, frequency of use, quality of drugs, personal chemistry etc. I think it's pretty clear that I'm not an injection drug user, or I would be looking far and wide for that nice, fluffy china white.
I've had really shitty quality oxycodone in the past as well, must have been expired or something. There are fentanyl counterfeits out there too to watch out for.
But 5mg, or even 2.5mg of the good oxy will have me in what I consider to be the perfect state of mind. Oxycodone is something I would take before any major life test: an interview, exam, public speaking, etc. as a performance enhancer. But I take it every day because otherwise I am bedridden in excruciating pain in my spine - I try to limit the amount I take per day to 5mg, because I don't want to build up a tolerance to such a wonderful drug. So far it's working out well, I have a mild psychological addiction to it which I am perfectly fine with having so long as it doesn't escalate.