Couchette??

IMO, a couchette is like staying in a Hostel, a little short on privacy, but livable.

In my case, up in years and a snorer, I would get kicked out into the hall in a few minutes. I don't use couchettes, but then I don't stay in hostels, either.

Carriages with couchettes usually have showers at the end of the car.

You spelled it correctly! Couchettes usually have bunks for either four or six people. Paying a little more for the four-bunk couchette is well worth it for the extra space and comfort. If you can afford it, you'll be even more comfortable in a sleeper that has real beds.

I've never used one. I'm not a picky sleeper but too many people have said it's not a restful night sleep because of the train stopping in different rail yards and picking up/dropping off cars. I seem to be able to nap pretty well in second class so maybe it's not that bad.

I recently used a six person Couchette on an overnight train from Stockholm to Oslo. There were showers at the end of the car.

Pros

1. At 6 foot 7 I was able to fully lay out and get better sleep than I would on a lie flat seat on an airplane.

2. I did not have to pay for my hotel room that night as I had no surcharge.

Cons

1. Obvious lack of Privacy & the Influence of others

2. Lack of space. By the time everyones luggage was in the area there was zero floor space. The 6 beds is also a bit claustrophobic at times.

3. Hot due to close quarters

All things considered I was able to sleep better than expected. In fact it was disorienting waking up at 6 am to find yourself stopped at your final destination.

Knowing we were going to get in at 6 am for a one time thing in Scandanavia made the couchette a good way to go for us. A nice night of sleep was not happening no matter what and as such we didn't pay a premium for it. I could easily see wanting more privacy, space, security on a longer trip in areas with more concern for crime though.