We went around the tip of south America on Holland America (Buenas Aires to Valparaiso). There were two long land tours but both ship operated., No problems. I have been carnival also. HA was far superior and no kids running up and down the hall at 3 AM
If you ever go to SA take time for Iguazu Falls, Spectacular with a huge Argentinian national park around them..
I have a dear friend right now who is doing a world cruise on Holland America. He is right now in the Seychelles. He loves Holland America. Has done a couple of their world cruises already.