First and foremost, we had sailed (river) with Viking before and were so impressed we had to try their ocean cruise. Second, the "Passage Thru Western Europe" 15 day cruise had a great diversity of locations that we wanted to see. This was our 5th cruise and 4th Ocean cruise. We wanted to go on a smaller ship, as we are not sure we want to fight the crowds, the casino's, constant petty sales and extra cost strategies on the bigger ships anymore--even if it costs more. We were definitely NOT disappointed with the Viking choice.
We started the trip by spending a week in Barcelona on our own, which we highly recommend, especially if your are flying in from a far away time zone. While Viking had a city tour (bus) as part of the trip--there was no way to see that great city in the time allowed. This is likely true of many cruises so we always come early and/or stay afterwards to take advantage of being in a great location and adjusting to the time zone.
Embarkation and disembarkation was super smooth and uneventful. Being a smaller ship helped I think as we never felt crowded. After we boarded we enjoyed our time relaxing with a stress free lunch without fighting the normal "cattle call" at the lido decks of most larger ships.
While bigger is always better, the size of the room was perfect for us, 338 SF and for longer trips having the extra space is important to us.