re: Carryon bag for international trip

Just my opinion but I hate rollers for Europe outside of the airport. If you are strictly carrying on then something like a rolling duffel with wheels that also has a single strap to carry or a backpack is much preferred.

Going through train stations, cobblestone streets, up tons of stairs, etc with only a roller sucks which is the case in much of europe outside of city centers and American brand hotels.

I see you are just discussing your carryon not only carrying on, if that's the case then yeah just make sure its small enough to fit the requirements. As said its more about the capacity when used then the capacity empty.