Well, that's pretty much the question. :-D Taking an overnight train is significantly cheaper than the daytime version, but what do you do when you arrive in Salzburg at 4 am?
On a similar note - we arrived in Salzburg at 5AM and went to our hotel. Luckily, the night clerk let us in and, because our room had not been occupied the night before, let us check in. Believe me, that was a real treat after the 12 hour-no-sleep-night train from Paris!!
The only night train that ever deposited me at a fairly reasonable hour traveled from St. Petersburg to Vilnius , at around 9 AM. In other circumstances, I deposited my luggage in the station lockers, and explored the city as it awakens, which allows for a unique perspective that many tourists never experience.
Thanks for the honesty guys! The previous few night trains I had looked at had reasonable hours, so this one left me with a "eep!" I think I'll just skip that one.
I had a similar dilemma as we were looking a train from Zurich to Salzburg that would arrive around 4 or so and we nixed that idea. I figured as much as we wanted to get a jump on the day and maximize our sightseeing, it wasn't worth only getting 5 hours or so sleep on a night train and then having to wander around a place i'd never been at 5am. Who knows though, if the weathers nice you might have some interesting views that early of the city with nobody out and about.
What I have done on occasions - but not in Europe, and it would depend on finances is book the accommodation for the night for the night you're on the train - explaining at the time of booking what time you will be arriving - just a thought, albeit not cheap. :)