They've recently reduced the number of busses/trips, so be prepared to line up in AC for the return trip at least an hour before the bus you wish to take. that's convenient, but that's also a problem. academy lets you return up to four days later from any casino they service.
Unlike regular megabus service, you don't have to specify a day and time for your return trip. the trip takes about two and a half hours, with no traffic. the trip going down is usually pretty good, although it gets very crowded on fridays and saturdays. arrive early or late and your ticket is invalid. Megabus sells you the e-ticket, but you travel on academy bus lines' scheduled service from port authority at the specific time you've chosen online and that's noted on your e-ticket confirmation. It's not really a megabus (the large comfortable wifi-equipped busses that go to baltimore, boston and washington or other large cities).