Swiss rail

Windows are the same size in first class AND in second. Do you want fewer people in your train car? If so go first class. If you actually enjoy meeting locals then try 2nd. They're both clean and both arrive at the exact same time.

Agreed; however if your travel includes the "tourist" trains then some first class panorama cars have bigger panorama windows. Me, I always stay in second on local trains which are just as fast, more frequent and save a shedload of money. And I can stick my head out. On the first class panorama cars the windows are welded shut.

Thanks for the information. As a follow-up, what are the seating arraignments in the two classes? Do the seats face each other in groups of four, or all face the same way? Are there tables between the seats? I can't find seating diagrams.

You're going to hate the answer. It depends on the train. Some are double decker with a playroom for the kids including, yes, a slide and dinosaurs. Some have back to back seating. Some have airline type. There is quiet a variety. Most facing seats have either large or small (and some convertible) tables - some semi circular others rectangular - with a trash bin underneath. The variety is especially obvious on the private railways, usually the scenic ones. The main line SBB/CFF/FFS trains are usually the double decker with big seats and dinosaurs or single decker older stock with large soft seats and smaller windows.