OW has a lock on parts of South America as well. LAN has one of the most consistent hard products in the industry. ime, LAN's longhaul business product is the equal or better of any airline flying to that part of the world.
BA permits me to fly in LAN's excellent J cabin rt from NY to SCL or IPC or EZE (with enroute stopovers if I wish) for 80k BA miles plus minimal taxes. Since I value LAN's J hard product higher than BA's own, I consider this specific alliance a very serious plus in the OW program.