I answered your post on the other thread about the methadone--hope you are able to check it out.
Methadone does take longer to taper off of than heroin--but that's not the point. If the only thing that was needed was to get the patient OFF the drug, we could simply toss them into a locked room for 5 days and all would be well. But as we know, that is not the case. Most patients need more than a simple detox.
There are some forums where you can learn more about methadone treatment. Try Googling "Addiction Treatment Watchdog", "We Speak Methadone", and "Methadone support.org".