Originally Posted by
theshaun
also, if seated in a 63K for example, would I have to climb over 64J if they are fully flat to get to the lav?
Yes, basically you do. This is one reason why 62AK and 64AK are the window seats that are most favoured; none of them require stepping over someone to get to the aisle.
(It may be possible, if you're slim, to squeeze between the seat and the cabin sidewall and go forwards towards the door, thus avoiding stepping over 64J. But this isn't the intended exit route from the seat.)
Of those four, though, only 64A is available for purchase if you're not entitled to free pre-allocation. The main categories for free pre-allocation from purchase are BA Golds and Silvers and OW Emeralds and Sapphires. BA Bronzes and OW Rubies get free pre-allocation from 7 days before the flight; I think that this includes all the other UD seats if any are still available.
The 747 UD is about as close to the private jet experience as most of us are likely to get.