Not a bad move taking row 80.
Be aware with 80H/K as your choice that a smart flier who was allocated 80J would surely use 80K as a bargain chip to negotiate any move/swap as it is a much better seat.
If you go for 79 you'd be paying extra $$ as QF rip people off to sit in the exit rows - well done bean counters. 71D/E is another optn.