In December 2007 and January 2008 we spent 37-days on the Star Princess with back-to-back cruises. We sailed across the Caribbean, down the East coast of South America, stopped in the Falkland Islands, sailed around Antarctica for 4 days, backtracked to the southern tip of South America, and ended in Buenos Aires. We then spent 4 nights at Iguazu Falls before returning to Miami.
We got a better rate by purchasing the 2 cruises as a package, plus we got the same cabin throughout the trip. It was cheaper for us to cruise to Buenos Aires where the Antarctic cruise officially started than to stay in Florida for 21 days and then fly to Buenos Aires (we travel all the time, so if we were not on the ship we would be staying somewhere else).
We are keen bird watchers. We selected this trip as a way of getting to Antarctica at a reasonable price and to visit other remote places we had not gone bird watching before.
At 2600 passengers, the Star Princess is the largest ship we have sailed on. We had a room with an "obstructed view" which wasn't very obstructed at all. We decided we didn't need a balcony since it would probably be too cold to use it much of the time in Antarctica - which it was.