Amtrak’s roomettes are pretty small, and the seats aren’t as comfortable as the regular seats, so for a short trip, I doubt you’d want one. We were going to be 10 hours, roughly, from LA to San Jose, and traveling in the daytime, so we didn’t NEED to lie down and sleep. But I was pretty sure Kavi would like having the option of stretching out and napping, and she definitely did.
Kavi and I are both on the small side (5’2″ and 5’0″ respectively, and we wear an XS and a M/L, if that gives you a sense), so it turned out that once we’d converted the lower chairs into a bed, which we did almost immediately, we could both stretch out there pretty well, especially if we were willing to be in some physical contact.
I did try dropping the upper bunk and climbing up to it. You need a little bit of physical dexterity here — it’s just two steps up to it, but then you have to kind of roll yourself into the space. There’s some straps you attach to the ceiling, so you can’t roll out while you’re asleep, and if you don’t mind a small, dark (no windows) enclosed space for sleeping, it’d be fine.
I read up there on my Kindle for an hour or so at one point, just so Kavi and I could both spread out some. But if you’re at all claustrophobic, I wouldn’t recommend it.
Worked well for us, though! I think it was the right choice for the two of us, for this length trip.