Yeah, that's the point I was trying to make before with my first sentence. A 5-6 hour flight isn't that hard to do in a seat; you don't need a sleeper for that

Yeah, that's the point I was trying to make before with my first sentence. A 5-6 hour flight isn't that hard to do in a seat; you don't need a sleeper for that. But a 2-3 day trip on a train isn't something you want to do in a regular upright seat.