From what I understand, the menus are the same no matter which cruiseline. Many ships alternate eastern/western caribbean, so if you didn't want to go to the same ports, that would be a good way to do it. Even if it did go to the same ports, that wouldn't bother me...I'd skip one on the first and get off there on the second. More sea days that way! I like the sea days.
Some people do back to back on different ships leaving the same (or nearby port). We were talking to a woman going from the Golden to the Sun Princess for a total of 17 nights...we were so jealous!
The advantages:
2 cruises, only have to fly once
longer vacation
more time to do things I want to do, see more of the shows
the disadvantages:
None that I can think of!
Try a search on the different boards about back to back cruises.
Having the same menu would not bother me. There are usual a couple of items at each meal that appeal to me.
It usual takes me a few days to start to relax and before I know it the cruise is over. I think that back to back cruises would be the way to go. Plus you say on airfare.
The menus being the same didn't bother us, as we could repeat something we liked or try something new that had appealed to us.
The entertainment was the same, and some things just aren't as enjoyable twice in two weeks.
Our two cruises had different itinerairies, which was a plus.
Princess couldn't give us the same cabin for both weeks, and having to pack, move cabins and unpack again was a hassle, wven with the "help" of the steward.
We always did back-to-back on Princess, most of them in the Southern Caribbean (with different itineraries each week). From our last one we got home last Sunday.
A b2b cruise is more relaxing. We always had the same room, so we don't have to pack or do anything to prepare for the second phase. We get to be known by the staff who get more friendly as the trip progresses. Also maximises the vacation time versus air travel costs. It was interesting to watch the mood of the people who are just doing the one week cruise, because the last day and night everyone's is preparing to get off and the vacation is over for them. After two week we are always happy to go home and we are not unhappy that the vacation is over.
Sometimes Princess offers two upgrades for a b2b, but not from inside to outside and not for minisuites and suites.
Did back to back in the med with a Trans Atlantic crossing as the 2nd part..the menues did repeat but as someone said there are usually diffrent things that you can order or do a diffrent dinning room. The entertainment was a bore but we caught a few movies and one nite played board games with some tablemates. We were on the Cuanrd Visitaford which is now the Coroina she a smaller ship.
We loved the entire trip, had drinks on deck each nite while watching the sun set, really got to unwind and know alot of people, including the crew, on the trip...10 years later alot of us are still in touch.