We did a B2B on Marina in June. Had a fabulous time in Northern Europe and UK. Marina was lovely, we were in a concierge cabin, room attendant was wonderful and prompt - no request was too small. Food was very good and selection was amazing; food service staff very helpful with regard to food allergy.
We prefer the O ships which provide more dining variety and space to wander - especially on sea days!
We have sailed on Marina several times and enjoyed this trip as much as previous. No complaints.