Differences between first and second class: Normally, first class is configured with three plush seats per row (whether in compartment or open-style seating) and second class has four skinnier, basic seats in the same space. Remember that nearly every train has both first- and second-class cars, each going at precisely the same speed!
Choosing first class: If you have the extra money, riding first class is less crowded and more comfortable. First-class railpasses can be a good value, too. While individual first-class tickets cost 50% more than second class, first-class railpasses generally bump your price up only 25% to 40%.