I've flown BA J, it's an excellent product but the fuel surcharge kills the value.

Though I haven't flown them, CX's J product is reputed to be excellent, and at 100,000 between the US and Asia I think it's a great value. That would be the way I'd go if you can transfer 20,000 miles into your AS account.

If you'd rather not do any miles transfer, LAN's J is also supposed to be very good (I've flown them in coach, and the service levels were fantastic). They fly all over South America, so you have some fantastic options of places to see. The ncie thing about a South American vacation is that once you pay for the airfare you can travel relatively cheaply.

I can't comment on any of the options to Europe other than BA (AA's changed their J product since I last flew it). Perhaps others can chime in on the relative value of J on DL, KL, AF and Icelandair? For me, I'd much rather fly CX J at 100,000 miles a ticket than DL at 90,000 a ticket.