The cruise itinerary was excellent, lots of time to explore some fascinating cities, and the value for money was reasonable.
I was disappointed that none of the traditional Italian foods I was looking forward to like pizzas, gelato and coffee were included, all were extra costs.
In addition, they lost my bag on disembarkation and made me trek around Stockholm trying to recover it, taking no responsibility for it - the tags they give you and say are needed to reclaim baggage are literally entirely pointless. One or two junior staff tried to assist but on the whole a really awful way to end the trip.
Wifi is expensive and no maps or anything are ever provided so without the wifi package it's not easy to get around on your own - and the shuttles into town provided by the liner are ridiculously expensive.
The ship itself was pretty nice, except that the slide never worked at all throughout, and most of the passengers were surprisingly pushy and rude.
Most of the other people I spoke to who had been on other cruises said they wouldn't use Costa again.