I like having BA gold in the US for the FL access and the QF F lounge in LAX.
I also keep AS 100k and unfortunately, AS will not let me in their lounge if my BA number is not on the reservation. I believe it's a sore point for those like me. I watched a BA gold having an argument with the lounge dragon in PDX...
On the other hand it's a minor issue as I go to CC card lounges or use one of my 4 lounge coupons from AS when I really want to go in.
As GGL, I've also had occasional help in DFW, PHX, and LAX. It has twice or thrice allowed me to make a connection that otherwise I would have missed in DFW. The cart between terminals made all the difference.
A few times I've been taken by car on the tarmac.
In DFW
In LAX
PS: I was paged to board with CKs and called BA VIP tonight when boarding in LAX 😉