I usually take the megabus because it is cheap and ok in comfort. However this morning as I was waiting in line I witnessed such poor customer service that I was outraged - and it wasn't even directed at me. They were not letting some poor girl who had a flight to Germany to catch on the coach because she had one additional bag (and a small one at that). Not that it would make a difference to them and they wouldn't even let her pay extra to put it on or buy an extra seat, as she cried and begged them.. And of course they had absolutely no morsal of sympathy and were horribly rude.
Moral of the story: read all the fine print on your receipt. Megabus's customer service is so bad they don't even nickle and dime you - they just don't let you on! Their luggage restrictions are tighter than an airplane's, and their customer service is worse than anything I've seen.