I also believe it is an improvement, as last year we left it early to ensure a relaxed experience through security and then visited the AA lounge whilst waiting for our BA flight, which we found vastly inferior to the CL and not worth it, so having the option to stay longer and going straight to the gate, made it of a nicer experience.

Mind you, the Amex app still reported it as located "Before Security" and give instruction to the old entrance, so we almost went back out whilst looking for it after security (we were informed of the location by the BA First Check-In desk).