-This may get moved to Basic Drug Discussion, let's see if I can throw my 2 cents in here before it does...
Methadone is an opioid/opiate like oxycodone (roxy, oxy), hydrocodone and morphine, however, methadone is a synthetic opioid whereas the ones you've taken are either natural (morphine) or semi-synthetic (oxycodone, hydrocodone).
Methadone does have significant recreational potential for sure (I've used it personally a few times, I prefer other opiates, but thats a matter of personal taste and nothing more), however, methadone does have a very long half life and a very long duration of action. This means that not only does methadone last a longgggggggg time (12 - 24 hours usually, sometimes much longer depending on body chemistry, tolerance, etc) but it also takes a long time to kick in, sometimes up to 2 hours.
Of the opiates you've done, morphine is probably the closest to methadone in my experience. However, your experience may vary, and I'm not the most experienced methadone user for sure.
Hope this gets you started in the right direction, I also recommend checking this thread out:
Methadone Mega Thread and FAQ