Opinions - Methadone or Subutex for SWIM?

[baron samedi]

SWIM is due to go onto one of these drugs to get him off his (at present) 55 grams a day poppy pod habit.
SWIM's shrink wants him to go on Subutex, principally because it is a much easier drug to come off. They also told SWIM that Methadone can have a dysphoric effect, i.e. make people miserable. SWIM is not sure whether this potential side-effect was mentioned principally to discourage SWIM from going onto meth, or whether this is a genuine drawback of the drug.
Thing is, SWIM's life has improved somewhat since he started using poppies again, giving SWIM confidence and making him feel good in a sence that he wouldn't be able to feel otherwise. Something tells SWIM methadone would be better for replicating the feelings he gets from poppy grounds (he just swallows the powder), but he could be wrong. Maybe Subutex would have a more energizing, anti-depressant effect on SWIM, enabling him to function better than on Meth.
SWIM has no experience of either drug, so would appreciate any advice from people with knowledge in this field.