Acela train's have different classifications. Coach is called business class, and if you want to upgrade you would do so to first class. Non-Acela regional trains have coach and business class. I think the best advantage to being in business class especially if you are boarding at a main station is not having to worry about having to deal with the cattle drive that often occurs to get a coach seat. It's usually much quieter, a bit more civilized and I still think you get served a meal or at least a complimentary non-alcoholic drink. It's also separated from the coach area so you don't have an endless stream of people walking by. I had vouchers for Acela upgrades for awhile and could never get into first class because it was always full, so I don't think you are really losing anything by going the regional business route.