I choose Fred Olsen because of the itineraries and because I don't like huge ships (I actually prefer those with around 300 passengers, so Fred Olsen ships are still bigger than I like, ideally).
Boudicca is comfortable and the food is very good - plenty of choice and variety, and the staff are friendly and helpful.
My criticisms would be:
Small and expensive for what it was - ie a single cabin, not a double for single occupancy. First cabin very noisy, but change quickly organised