>>1970030private sleeping train operators have really old rolling stock around. European Sleeper are renting a AB30 made in the 1953.
really speaks for using steel for longevity, modern trains with aluminium body should be replaced after 30 years because of material fatigue.
one criticism of using continental rolling stock in Scandinavia is that they might not be properly adapted to the winter up there, people using flixtrain (former DB coaches) in Sweden complain that the trains are cold in winter.