I'm on it tonight, westbound. In a couchette. It feels like being in the 1990s again, except that people have smartphones and I'm three decades older.
Certainly it's a bit different to what most people's expectations of a train are, in western europe now. Things are a little rough around the edges (this is fine with me, but I wonder what some, especially younger, passengers make of it). The staff are friendly, not like the gruff conductors you might have encountered if it really was still the 90s.
It seems moderately well populated and we've not got to Berlin yet - I'm curious whether a lot of people will join there. I got on at Bad Schandau and was the only one doing so.