AOTG: Yes the so-called “premium” security channel in the North Terminal is seriously poor owing to its poor layout and single queue. Beyond that, having only very recently experienced both BA lounges, we considered Galleries to be far better to the First Class lounge. The lack of hot food may be an issue for some but Snr Mgt and I both enjoyed the salad on offer last weekend plus the various other food options. The place was busy but considerably better than hanging around downstairs in the shopping mall.
And is it not the case that travelling from the USA, you have to collect your baggage before checking it in again for the domestic leg because it needs to go through HM Customs clearance before any domestic leg?