We have used Viking several times now and have rarely been disappointed.
Everything is planned to the last detail, and because the ships are relatively small there are no queues when coming or going ashore. There is always somewhere to sit and relax with a coffee or an alcoholic drink without too many people around.
If a problem does occur it is dealt with quickly.
Cabins are adequate in size and are of a high standard. We had a small balcony which is great if you want to just chill out after an excursion. It is worth paying a bit more for this.