Globaliser

I imagine that most people entitled to use the First Wing would be entitled to use North Security Fast Track, about which I've seen practically no complaints. The entrance to that is much closer to the Heathrow Express lifts. If you were taking a flight that goes from the A1 end of the terminal, walking for 3-ish minutes to the First Wing, going through the First Lounge and then walking all the way back to the north end of the terminal through the crowds at shopping gate level is almost certain to take longer than clearing Fast Track North and going down the escalator immediately opposite the exit from security. And if you had a flight from that end of the terminal and you didn't have long to wait, it would seem largely pointless to go to the South lounges.

However, I agree that if you're going to one of the South lounges anyway, then the walk at check-in level is something you'd probably want to do.