I feel that certain opiates all have their own place.
If I am at home just relaxing, definitely IV heroin, and lots of it.
For everyday functionality, methadone. I am on MMT and still get a nice glow from it, and if I double get get a nice all day high. Strange I guess, but it is what it is. If it wasn't so hard to fucking kick it would be perfect. Combined with some valium+weed and I'm in heaven.
For pain relief, IV dilaudid is about all that truly works with my tolerance. I had a tumor on my spine and nothing would help me. Not fent, not methadone, heroin barely, but IV dilaudid (like 20+mg shots) made the pain melt away.
I'm a strange person i guess but I like what I like.