Make no mistake, Methadone is a pretty dangerous drug to the novice Opioid/general drug user. What makes it so dangerous? Well, I won't mince words here. Methadone carries with it a significant risk of respiratory depression, as do virtually all Opioids. It's a potent Mu agonist, just like Morphine and according to clinical reports, may produce proportionately more severe respiratory depression mg for mg, although I don't have references right in front of me at the moment.
Why are novice users most in danger (besides brutally obvious rationale)? Well, I believe I can say with safety that the majority of drugs used today in a recreational fashion have a relatively predictable course of action. It will vary by ROA and other variables, but in general, if one consumes a drug, they can expect the onset of effects and for that matter the duration, to follow at least relatively similar paths. If I eat an Oxycodone pill or an Amphetamine or a Benzodiazepine, I will typically expect effects within 20 mins - 1 hour.
For one who is only meagerly experienced with drugs, Methadone can be dangerous because it can take at least one hour for primary central effects to really kick in and up to 5 hours for some for maximum respiratory depression to be reached. This throws a lot of people off significantly. Maybe, they hear how powerful Methadone supposedly is and are let down when they don't feel much around the 45 min - 1 hour mark. Maybe they decide to drink a couple beers or pop a Benzodiazepine as to "not waste the experience". As they slowly drift out of consciousness, minute by minute, they become much less likely to suddenly come to the realization that they are over-intoxicated.
It's my firm belief that this is the primary danger associated with toxic overdose when Methadone is compared directly to short(er) acting agonists of the same type like Morphine/Heroin. As far as recreational benefits, that's not something I or the forums like to establish as primary topics of discussion.
As a post-script, do a little research concerning a drug that was produced in a significant way in the 60's known as DOM (2,5-Dimethoxy-4-methylamphetamine) alternatively known as STP (Strength, Tranquility, Peace) on the street. I think the concensus was that it was just not a great drug anyway, but a lot of folks who were used to taking the relatively faster-acting substance LSD-25 (Acid) often had difficult experiences as they would re-dose before the effects of the original dose became apparent. It's an analgous situation, but I feel it totally rings true, save that the DOM was not nearly as acutely dangerous as something like Methadone, with the primary consequence being panic, anxiety etc.