If you are used to the fine food that is served in the main restaurants aboard cruise ships or even river cruises such as on the Douro or Nile then you could be in for a nasty surprise with A-Rosa. It is not much above that of motorway services or cross channel ferry fare. On our last night it did improve markedly but up till then it was very basic.
The house wine is awful plonk reminiscent of the kind of stuff British pubs used to sell many years ago before the customers demanded something better.
Breakfast was also uninspiring Germanic fare i.e. cold meats & cheese, with very little hot food unless you were prepared to wait for a small omelette. On a cold winter sailing like this a hot breakfast would have been nice.
On the plus side, the staff are very good, very friendly and very efficient.
Cabins are quite nice with a lovely shower. However I would not have wanted be be on the lowest deck where your window is only just above the water line.
Excursions to the Christmas markets were very expensive and if this in indicative of their typical excursion prices then [apart from the poor food] I would not want to do a summer cruise with them.
If you are looking for a Rhine cruise then I would suggest you check out other operators.
Reasonable space. Nice picture window. Reasonable bathroom with excellent shower.