I did the quick turn around last April. I had a USA passport and was traveling in first class. I did not get a boarding pass in London, but when I arrived at the lounge, the staff said they would go to the ticket counter and get the boarding pass for me as the counter was not yet open, It took me a few minutes to figure out that one descends one level to the transfer desk instead of two levels to the arrivals level. Still must go thru security at the transit level. As for the duty-free shopping, I was underwhelmed. Few if any Sony products (looking for the noise-cancelling ear phones),