Choosing between the Green Car (first class) and ordinary cars on Japan's trains depends on personal preferences for space, budget, and comfort. Ordinary cars are exceptionally clean, quiet, and comfortable, featuring ample legroom that surpasses standard airline seating. Green Cars offer wider seats, greater recline angles, footrests, fewer passengers per carriage, and an extra layer of quiet ambiance. While Green Cars provide a more luxurious experience, ordinary cars offer fantastic value and high standards of travel convenience for most visitors.