Since it seems to be NTC F, I would do it in a heartbeat. I find their F product very comfortable, and it makes a huge difference over the slippery C seat (NTC) - let alone OTC C or any Y seat.

Another option might be a Skyteam award via the US - Delta flies ATL-SCL non-stop. It depends on one's personal taste, but I do like their product and the service on board.