I'm hesitant to answer definitively without going back to check old threads (of which I suspect there are many, not least the seating threads) but from memory it's more that in 1a etc, the back of the seat curves with the fuselage and gives less space to sit back. All F seats on the 747 are less roomy than the newer aircraft. You may find buddy dining less comfortable than A380 in any seats, although I have seen plenty of people enjoy it on this aircraft over the years.

The other thing to keep in mind in favour of 1A and 1K is that they are both window seats but you can chat much more easily as a couple whilst both enjoying the view from the nose.

Maybe check the flight loads as you come to T72. If they are low, there's a good chance you can have your cake and eat it by nabbing 1A and 1K, and having some buddy dining set up at another seat. The flight crew will have no problem doing this as long as there are a few spare seats. (or vice versa, but you may find someone else moves onboard if they see the front seats free!)