Long time to peak for sure, but also potency varies greatly (increases) when taking several days in a row. Let's say you take 20 mgs with a low tolerance on day 1 and on day 2 you feel like you could take at least 20mgs (if not knowing the fat storability) could easily overdose even with the same dose. I don't think this is possible with any other opioid, which makes it particulary hazardous.