We had a 787 for SCL>IPC>SCL and found the seat very comfortable to sleep, lots of leg room and for a day flight, was offered pillow and blanket.
If we were flying longer than the 5hrs or an overnight, I would have picked the middle seats so we both have aisle access and pack pjs.
Thought the staff were not as polished as some of the other airlines but overall pleasant service and attentive when approached.