Last night I caught the night train to Lviv. A roughly 8 hour journey, leaving Kiev at 10:42 and arriving around 6:30.the train actually has sleeper cars.
Staying in hostels and speaking to others-I have heard lots of stories-that the compartments are open so you are sleeping in a giant room next to strangers (which might be true in other trains), and that lots of people on the train are drunk, so it is hard to sleep.
Well-I had a separate compartment-with 3 others. A couple and child who looked about 8 years old, so they proved to be pretty quite. We talked a little-as much as we could, considering their English was pretty limited.
The compartments we're basic-there we pull down upper and lower bunks, both furnished with vinyl covering. Sheets and pilowcases we're provided.
I kept my camera bag on my upper bunk, because I didn't want to lose it! (or have it stolen by a couple of parents and child)-and the bunk was small, so my feet we're elevated the whole time! While the bed wasn't real comfortable, relaxing to the rocking of the rails was quite comfortable (I still didn't sleep much). Before retiring, I went to the bathroom to brush my teeth, only to find out that there was no running water in the sink. I slept in everything I wore, including my sweatshirt and shoes.
About 6:15 am, or so, a conductor knocked on the door to let us know we are almost there (I think-it wasn't in English), so I got down from the bunk (no need to get dressed-I still had everything on including my shoes) and got ready to get off the train, and explore Lviv at 6:30 am.