My husband and I took our first Viking River Cruise in 2011( Christmas Markets). After friends heard our how we loved it, they accompanied us in 2013( on the Rhine). In 2015 we stepped up to the Ocean cruise with yet another couple. (3 in total).
Having been on the smaller river cruises , we did not know how we would feel on a larger ship. I tell you the worries were unfounded. The crew is professional and accommodating. The ship was beautiful and plenty of space for 900 passengers. I felt as if we were on a floating hotel and we had plenty of places to explore and relax after a day of sightseeing and a wonderful dinner. There was no "crowed" feel. All our meals were delicious.
The excurssions were a little disappointing ( i think they are on all cruises) I personally would not do Pisa ( yes you need to see the Leaning Tower , but not really) Toulon, I would not choice Aix and on Corsica, there is no need to take a 3 hour bus ride around the island, although the brief stop at a local tavern was very nice. In Monaco we took the bus to Nice. ( cost a 1.50) Oh and a must see is Monserrat while in Barcelona. And I wish I had 2 days in Florence and a week in Rome!!! Two beautiful cities and so much to see. Our guides in these cities were spectacular!