I agree with sdorling that LAN J has the best J hard product in OW currently.

Not a huge thing at all, but worth remembering that the 763s only have restrooms on the left side of the plane. If seated on the right side, you're typically having to either inconvenience sitting FAs or displace f&b carts (or, hopefully not, jump over other J passengers) to cross over to use one of the two restrooms.

Also worth remembering that SCL has a separate security area for J passengers immediately beside the J check-in area at the far end of the airport. It may have been sheer coincidence, but each of the 3 times we used it this past January/February there was literally no-one in line in front of us, which made it an extremely valuable J perk.