I chose the Sarajevo-Mostar train as my trip. He travels for about 3 hours along the serpentine, the cars are already modern (Talgo), the only disadvantage is that you can't buy a ticket in advance, only every day and you need to carefully check their departure time (usually 2 times a day in this direction).
Tickets are cheap enough (August 24’)
Otherwise, everything is not bad, there is a cafe / toilet at the train station.
There is also no waiting room (