One thing I would call out being lie-flat on the throne seats is that I do find sometime bothersome the traffic on the aisle - while service is ongoing you can really feel the shaking/vibrations as the FAs are going repeatedly up and down the aisle, I swear it's akin to stomping sometimes if they are a bit in a hurry with service. Maybe it's a question of how light of a sleeper one is, but something to consider for those red-eye flights where you're looking to get some sleep shortly after take off, while service is still ongoing for the rows behind you. (Also to mention that the J lavatories are only on the right side of the a330, i.e. the aisle adjacent to the K throne seats, hence some added passenger traffic because of that as well).

My last red-eye on the A330 I went for 2K as I saw 2H was unoccupied at check-in, very quick meal service and best sleep I've gotten on EI J. Was worried about noise from the lavatory, but didn't hear a peep. Also could have sworn the footwell felt wider than the throne seats, although that might have been me getting carried away after my good sleep ha.

TLDR: consider 2K if you're a light sleeper and 2H is free or travelling with a companion.