This is probably mostly of interest to my future self, but a couple of weeks ago I went for a few days to Penzance, and the trip down was by the Night Riviera (sleeper) :-

Taking a sleeper was … interesting, The first thing to note is that if you’re big then the corridor within the coach can be a wee bit claustrophobic. The cabins are also rather small but oddly not so claustrophobic. The bed is … well kind of narrow.
Funnily enough it was quite easy to sleep whilst the train was running; in fact I woke up when the train stopped. But for me it wasn’t restful and I arrived in need of sleep.
And you arrive at the wrong end of the day – 7:50 in the morning well before you can check-in to a hotel. That isn’t the fault of the train of course; if anything it is the fault of the hotels assuming that you will arrive later in the day.
The more interesting … or perhaps amusing journey was the return :-

This was a day journey … or rather three journeys – Penzance to Exeter (with a reserved seat), Exeter to Salisbury, and than Salisbury to Portsmouth. Just the standard long distance train journey that so happened to leave me without any platform wait long enough to get anything interesting to eat.
But even more amusing was the first leg of the journey – there was no 09:18 train; instead I caught a 9:11 train. And of course my seat reservation was for a fictional train; the seat was reserved for someone else who happily didn’t turn up.
But when I pay for a train ticket I expect it to be for one that actually exists. Similarly I don’t need a seat reservation for a fictional train.