I've been told by most people and online sources that at th point where suboxones opiate effects plateau, it has the agonist activity of 30 mg of methadone. I've also heard 50 and 60, but nothing above that. And I believe suboxones cieling limit is definately reached at 6-8 mg for me when taken sublingually. I'm on suboxone now, so of course I'd like to switch it up and take some methadone, but if I were completely non tolerant on opiates, I would go with suboxone, as it is the only drug that has ever allowed me to stay really high for two, sometimes three days. Methadone just lasts one day followed by a shit hangover