if you smoke ...read this , page-18

Rinsterm
We are a bit off topic on this thread as it is mainly about smoking.
However to comment on your post.

Methadone V Heroin.

The problem with Heroin is has a short half life so it needs to be dosed frequently to prevent withdrawl symptoms.
For obvious practical reasons, in a treatment programme, this is a real disadvantage.

A Methadone patient only needs to be dosed once per day which means they can got about their daily lives without too much inconvenience or disruption.

Nothing is perfect and there is no simple answer.

Cheers

Bendigo