I use lobster as a benchmark to check to see what cruise lines are better than the others as far as food is concerned.
There should be one lobster night in the main dining room on all good cruise ships.
As far as I understand, many cruise lines do not do this.
They are:
NCL, RCCL, Carnival, Costa.
It should not matter how many days you cruise to get lobster in the main dining room.
If they do not have a lobster night, I book elsewhere.