Seats will probably turn out like on the A380 where someone doesn't like a certain seat due to galley noise yet someone else had no problem. I personally have had 53A on a night flight and wasn't affected by banging of trolleys, cutlery clanking etc. like some people. Easy to get out behind your seatmate as well without climbing over them.

Don't know if I would go for 7AB due to the toilet but I suppose that's no worse than 64K on the UD of a 747. Easy aisle access and a more intimate cabin.

As you're in a pair, and if you decide to sit together, at least getting out won't involve you straddling a stranger

No idea what the windows are like should you want 2 or 3, certain alignments etc.