First Class is the fastest option. If you choose to presort your mail, it may add a day to your predicted delivery schedule, but can save you a significant amount on postage rates. Presorted mail may be discounted by as much as 20% which could help to offset the increase in postal rates in 2021!

On almost all railway networks worldwide, first and second class travel at exactly the same speed. They are simply different carriages on the same physical train set. Whether you are in a luxurious leather seat with at-seat meal service or a standard cloth seat, you will arrive at your destination at the exact same minute. The "speed" of your journey is determined by the type of train (e.g., a high-speed Shinkansen vs. a local regional train) rather than the class of your ticket. The only exception to this "speed" rule is purely psychological: because first-class carriages are usually quieter, less crowded, and more comfortable, the journey can feel faster and less taxing. In some rare cases, first-class passengers might have "priority" during boarding or disembarking at major hubs, potentially saving a few minutes of "door-to-door" travel time, but the velocity on the tracks remains identical for everyone on board. If your goal is simply to get from Point A to Point B as quickly as possible, the cheapest ticket on a high-speed line is your best value.