I think it is unfair to say BA is losing its edge. It has excellent lounges throughout its network which beats any airline. The newclubworld seat is great and the service on board is good. In my view BA is still my preferred airline – though I tend to fly domestically and North America and so cannot comment on other routes. Apart from some new mixed fleet flights, I cannot crticise BA’s products and have always found them to be flexible, and with changing domestic flights (except LHR) but you cannot expect that as it is just a bonus when it happens.
AA is a different market and AA domestic fares are cheap and I have always found their flights to be ok. But AA lounges have always been very friendly and nothing too much trouble.