So we are home. We got up early and cleared our rooms before breakfast, and after it we sat in one of the lounges and read for awhile. Probably we should have sat awhile longer, as we had a long time to wait at the station, but not enough time to go and do anything other than a brief leg-stretch. However, eventually our train was called. As predicted, it was rammed, and I was glad we had booked seats, as otherwise we might have ended up sitting on the floor, as some people had to do.
There seemed to be an extraordinarily long time to wait in Brussels, too, although I'd booked us on the recommended connection. But eventually we were on the train back to London, where I extravagantly insisted on taking a taxi home, as I was so very tired. And, although I managed to unpack, I have been asleep practically ever since!
So what about my impressions of a river cruise? It was lovely! I thoroughly enjoyed it, and would love to go again in a few years. I think, though, next time I won't book all the excursions in advance - although we enjoyed them, some of the walking tours were unnecessary, as we could have explored for ourselves. On the other hand, the guides did tell us a great deal of history we might not otherwise have known, and they were (mostly) obviously passionate about their towns.
We didn't much care for the cruise director - he came across as extremely patronising, and even rude on occasion. Also unprofessional, tearing a strip off one of his colleagues where anybody could hear, rather than doing so in private. But he was a minor irritant.
The food was mostly excellent, except when the chef tried too hard - but there was only one dish I really couldn't finish, and I do seem to have come back rather fatter than when I left. The cabins were comfortable, and it was lovely lying in bed at night watching the river going past. The big disadvantage of a Christmas cruise, of course, is that you don't get much, if any, daylight sailing. On the other hand, in the summer, the rivers and moorings are packed with tourist boats, and you have to clamber over other ones to get to yours!
I still want to do the "long trip" from Amsterdam right down to Budapest and beyond, but perhaps not this year!
By the way, TUI is a budget option; I don't know, though, what more you would get on a more expensive line!