We chose this trip primarily as on opportunity to visit northern Australia (Darwin, Broome, Geraldton) in a cost effective manner and reasonable time frame.
P&O and Princess Cruises (& probably all lines) have embarkation and disembarkation down to a fine art. Having had a long career in logistics I marvelled at the smoothness of disembarking 2000 passengers and embarking the same number, cleaning all cabins, replenishing stores, doing necessary maintenance etc within the space of 8 hours. Of course there are crowds and some confusion as everyone mills around, but once one is in the right queue it is a very efficient process. Given the number of passengers ships carry (1600-3500) delays are very reasonable.
Once aboard finding your way around is similar to any large hotel, except the ships provide maps. As a generalisation cabins are smaller than hotel rooms, but are well designed and more the adequate for two people. (I shudder to think of 4 persons sharing the space though!)
Avoid! As advised on board when choosing a cabin look at what is above you, what is below you, what is next to you and what is around you.
Deck 6, which I booked, is below the promenade deck. Whilst is was well insulated from most noises the squeaks, rattles and bangs where most unpleasant and made sleeping a nightmare. Many of the fittings were loose, a cabin cupboard door hinge was broken and the use of WD40 essential. However we believe that part of the cause where the lifeboats strung above, some of which had fittings hanging loose. (Not something that encourages confidence of their reliability in an emergency!)
Beds where good, space and storage adequate for 2 passengers (forget 4 sharing!), clean and well appointed. ONE solitary 240v power point is inadequate. Bring a 3m extension cord and power board!!!) Cabin steward was excellent. TV was very much "touch and go" and subjected to constant loss of signal and pixelation.