We sailed a year ago on the Eclipse on a similar itinerary and liked the idea of sailing for two weeks without returning to port after seven days so we booked again.
Embarkation was a nightmare and if Celebrity just communicated what problems they were experiencing it would have been acceptable. There were not enough staff checking people in particularly for the non-preferred cruisers.
We chose a balcony cabin starboard on Deck 6 midship. It was a perfect location for us as it is right behind the elevators. The cabin could use some updating but our steward kept the room clean and his service was exceptional. The balcony was large. There was some noise from deck 5 below at times.