I had an extended balcony Britannia room midship on L6. The room was tight but sufficient. There was a small desk, 2 bedside drawers, wardrobe space, under the bed storage, a small fridge, small kettle, with tea and coffee sachets and little packets of biscuits every day, and small chocolates in the evening. There was a complimentary bottle of champagne. Room was serviced twice day.
The bathroom was compact. Pressure of water was good with lots of hot water. Pump pack bottles of shampoo, bodywash, hand soaps and body lotion were provided.
A room keycard is issued to you for all purchases on board and for entry on/off the boat. You can buy an overpriced lanyard for US$8.