Holland America is always wonderful, in my opinion. We would have preferred Rio as a port as well. But I'm a school teacher and the timing for this cruise was perfect. 12-22 thru 1-05. Other cruises would not have worked.
I believe the itineraries are similar other than Rio. We are looking forward to the cruise. The Argentina side may be a bit rustic and not too much to see, I'm afraid. The penguins will be wonderful to see, however.