Has anyone done South America on Oosterdam?

[LindaJ+]

Santiago ... around the horn ... to Buenos Aires ... or vice-versa?  With or without an Antarctica sail-by?

[CruiserBruce]

Don't believe Oosterdam has ever done that route. It was done more frequently by the smaller ships in the past.

[RuthC]

Absolutely, include Antarctica. If you are going to go all that way, you might as well see the prize. 
Which direction is more a matter of preference and timing. 

Heading east to west you are one hour closer in time zone to home, so that makes the return flights a bit easier. If you do Antarctica, you also get to ease into the continent when you start to see small pieces of ice in the water, they grow slowly larger, and eventually you see massive bergs as high as 300' and longer than you can imagine. It is very impressive. 
However, that also means that the icebergs in Chile are anticlimactic when you do get there. 

Now, going west to east you will be more impressed by the Chilean fjords, but less impressed as you leave Antarctica. I actually felt sad as it was visibly over so slowly. Really, though, it's closer to a coin flip as to which way is better. Do consider the long flights down and home when deciding which direction to sail. 

My first trip home was from Santiago, and it was a 33 hour 'day' from the time I got up on disembarkation morning until I arrived home. My second time was also from Santiago, but was a 36 hour 'day'. Third time was from Buenos Aires and I got smarter and took a non-stop to NYC, then a limo home to RI. Oregon is much different flight routing. 
Do plan to take at least one day, two is better, to recover a bit before the cruise. Time to recover after coming home is also necessary.