We took a night train from Bologna to Paris, making this the second overnight train I have taken. The first (in 2008) was a pleasant experience. My then-fiance, my best friend and I were is a 6 person couchette with 3 adorable older French women. We all slept fairly well and the trip was uneventful.
This train? Not so much.
It started out being about an hour late (and we were early to the station), and once we got on we soon found that one of the toilets was completely closed off (all night). I don't know if someone was camped out in there illegally or what. But the remaining toilet was gross.
As we progressed, we found that whoever was driving the train was on crack and couldn't stop or start without jerking like crazy, making for a relaxing night. *blink* And the fun part was that we got into Paris AT LEAST 2 hours late- we were supposed to arrive at 9:15, then allow 30 minutes to get to our apartment, and voila! we are done! We didn't have a good watch, and when we did finally get to the apartment, we thought we were only a few minutes late for our 10am meeting. Try 2 hours. Our contact was long gone, so we made it to one of the other apartments, used the phone to contact OUR person, and I used 2 metro tickets to get to her place and back to get the key!
Our relaxing morning turned into a run around of trying to get everyone into their appropriate places, but we made it!
So in regards to night trains- I recommend them in general, but try not to take them from Italy- the train we were on was cared for by Trenitalia, and they didn't seem to care as much about the quality of the travel experience, plus the cost of the tickets was much higher than it should have been for quality of travel we received. I think next time we'll just try to get a later night flight from one of the cheapo airlines that are abundant in Europe. I hate all the time wasted on air travel (getting to/from airport, etc), but at least there would be a chance to sleep in a bed. We shall see:)