Personally I think some RX opioids have WORSE WDs than dope (fentanyl, methadone, oxycodone in high enough doses from what I have heard from people who have gone through both (I have gone through fent WDs (100x worse than dope once you are up to 25mgs a day or so) and methadone (40mgs a day wasn't TOO bad but lasted forever, 90mgs a day was 10x worse than dope AND lasted forever) never oxy at any level other than like 10mgs a few times a day, but I've heard from people who are using 80s 3-4 times a day (or now usually a couple 30s multiple times) those WDs are worse). I don't know why so many people say H has the worst WDs as I have experienced worse from opioids that are prescribed in cases. Also, even coming off like 1mg a day of clonazepam (well prescribed 2mgs a day, dropped to 1/0.75 a day for a couple weeks then stopped) was as bad as dope but that is a whole different class (alcohol- even worse)...
Now, I do think in OPs case they will get worse when he switches to H as it is hydro (and I'm guessing not HUGE doses as hydro doesn't come in very big doses with APAP). But to say "hey, you could go for any number of other pharmacuetical opioids..." some people will feel those WDs worse than dope. I think fent is the absolute worst by far (and it only took like a couple weeks to go from about 300mcgs IV per shot to literally 1-3mgs per shot)....