My experience in Italy is that certain routes (for Example X city to Y city) might be all unassigned seating; while other routes have all assigned seating. Point being, either all seats are assigned at the time you buy your ticket, or no seats are assigned.
In Poland it seems that if you buy your ticket in advance -- especially online -- you can get assigned seats... but then there are other travelers who have tickets but NOT ASSIGNED SEATS. So, these travelers hang out in the vestibule after boarding until the train gets underway, and then they walk up and down the train, checking seats, and asking the conductors for suggestions. Seems very inefficient -- and frankly stressful for the person without an assignment.
Rebecca and I were not seated together, but only one row apart, and her Old Lady seatmate was almost frantic because she was trying to be on the train with her daughter, and I guess they had arrived separately and boarded separately, and she kept calling the daughter on the phone and saying "I'm in this car, where are you??"... and then she said to the daughter in English "Yes, come here, I have a good seat and the lady next to me is American. You can speak English to her."
So finally the daughter shows up and she was pretty rough - she's recently finished either chemo or an extended stay in a drug rehab facility... and she has this pervasive smell of fish about her... and she and the mother have extended conversations standing in the aisle while the daughter is taking off all her (normal Poland) layers... and then she embarks on this 10 minutes process - sits on the floor (instead of in the seat, god knows why!) removes her snow boots, adds some extra socks, and puts on some other boots.
And it's at this point that I realized why I prefer riding in First Class on trains.