We chose to cruise with Fred Olsen primarily because of the close proximity of Edinburgh to their Rosyth embarkation port.
Also, we had cruised with Fred Olsen twice previously and knew them to be a solid, reliable operation giving value for money with the staff impeccable in every sense. Seven days was an ideal duration for us, too. in current circumstances.
Another stop (we went to Heligoland, Hamburg and Bremen) would have been welcome but there was more than enough to occupy us on board. A typical day comprised sightseeing or Scrabble, cinema, gym., drinks, dinner and a show. Perfect.
Not sure about the difference between an Inside Cabin I or H but it was perfectly adequate for our purposes. Clean and plenty of storage for two people.