We took DLP's version of the Magical Express round trip from CDG to DLP and back. It was extremely easy, but the Marne Le Vallee station is right at the gates of DLP, so it's a personal preference I guess. The bus didn't even stop at Orly, but that was likely due to the fact that it was in November. Disney does take a night trip into Paris that is nice and effortless, but if you plan on going to Paris for the day (we did a couple of times), best to consult the fanstastic concierge and do it yourself. At night, I was not comfortable navigating public transit during that time, as there was an active terrorist threat that resulted in law enforcement standing every night in downtown Disney with AK-47s in full view. Disney and guns in that proximity unnerved me. Have a great time!