We were also on this cruise and agree with everything mentioned by Oscar.
We sailed on Ex2 from Newcastle last September to Iceland and the experience then was a lot better. Better food, better service & better entertainment all meaning a better experience with better value for money. Having said this, this cruise was still good (just not as good as 8 months ago).
We have also cruised on a few of the other Marella ships, even the old Dream and things have changed quite a bit for the worse unfortunately.
We had really long waiting times in the MDR and when food did arrive the quality was not there (beware the Lasagne in the Vista about which we complained to the senior dining room supervisor ). In Nonna's restaurant last night it took the staff 3 attempts to bring the ordered drinks and this was only 2 x cans of Diet Coke !!!
The same Cocktails ordered in different bars were frequently not made to the same standard and some were just plainly rubbish.
The crew are not to be blamed directly but much rather the senior management team at TUI/Marella who set the strategy and corporate approach are responsible. TUI/Marella are obviously cutting back on their costs however they will need to be careful to not diminish the product too much to make it unattractive, especially since their pricing does not make them as attractive an option as they once were to the bigger cruise lines.
Overall it was a good cruise MAINLY because the weather was brilliant and the destinations were all excellent, as opposed to anything that Marella did.