Unless your flights are operated with Embraer or Saab aircraft, there is a difference between C and Y onboard service. IMO you can expect either a cold meal or a cold breakfast on most AMS-ZRH and ZRH-AMS flights, which I usually find to be tasty. In Y only sandwiches (croissants for breakfast) are served. For ZRH-MXP I think it is drinks and sandwiches in both classes, and for ZRH-FCO it will be a cold plate or even a warm meal in C, and a smaller meal in Y.
Considering lounge access and use of check-in lines as extra benefits, I would go for business.