Yes, they are fantastic. If you have any doubts about spending the best part of three months on board a ship it is possible to book for one or two sectors of the world cruise. This, of course, will mean flying which has limitations especially on the amount of luggage you can take. The only thing that you have to take into account is that on some world cruises you will have long periods at sea eg when crossing the Pacific which some people feel a little too restrictive.It is good value for money.
Do not forget that excursions /tips /laundry /insurance /fuel supplement drinks /are provably not included in the price this will ad a considerable amount to the cost of the cruis.
Yes they are on really long journeis the crew know you you know them and the ship and can really relax and have a great tim.